CveMateVulnerability intelligence

Cloudflare vulnerabilities, page 3

67 vulnerabilities

Known vulnerabilities in Cloudflare products, newest first, with CVSS severity, EPSS, KEV listings and ransomware use, across 30 products.

CVE-2026-2835Crates.Iopingora-core+27mo ago04-03-2026 23:32

An HTTP Request Smuggling vulnerability (CWE-444) has been found in Pingora's parsing of HTTP/1.0 and Transfer-Encoding requests. The issue occurs due to improperly allowing HTTP/1.0 request bodies to be close-delimited and incorrect handling of multiple Transfer-Encoding values, allowing attackers to send HTTP/1.0 requests in a way that would desync Pingora’s request framing from backend servers’. Impact This vulnerability primarily affects standalone Pingora deployments in front of certain backends that accept HTTP/1.0 requests. An attacker could craft a malicious payload following this request that Pingora forwards to the backend in order to: * Bypass proxy-level ACL controls and WAF logic * Poison caches and upstream connections, causing subsequent requests from legitimate users to receive responses intended for smuggled requests * Perform cross-user attacks by hijacking sessions or smuggling requests that appear to originate from the trusted proxy IP Cloudflare's CDN infrastructure was not affected by this vulnerability, as its ingress proxy layers forwarded HTTP/1.1 requests only, rejected ambiguous framing such as invalid Content-Length values, and forwarded a single Transfer-Encoding: chunked header for chunked requests. Mitigation: Pingora users should upgrade to Pingora v0.8.0 or higher that fixes this issue by correctly parsing message length headers per RFC 9112 and strictly adhering to more RFC guidelines, including that HTTP request bodies are never close-delimited. As a workaround, users can reject certain requests with an error in the request filter logic in order to stop processing bytes on the connection and disable downstream connection reuse. The user should reject any non-HTTP/1.1 request, or a request that has invalid Content-Length, multiple Transfer-Encoding headers, or Transfer-Encoding header that is not an exact “chunked” string match.CVE-2026-2833Crates.Iopingora-core+27mo ago04-03-2026 23:20

An HTTP request smuggling vulnerability (CWE-444) was found in Pingora's handling of HTTP/1.1 connection upgrades. The issue occurs when a Pingora proxy reads a request containing an Upgrade header, causing the proxy to pass through the rest of the bytes on the connection to a backend before the backend has accepted the upgrade. An attacker can thus directly forward a malicious payload after a request with an Upgrade header to that backend in a way that may be interpreted as a subsequent request header, bypassing proxy-level security controls and enabling cross-user session hijacking. Impact This vulnerability primarily affects standalone Pingora deployments where a Pingora proxy is exposed to external traffic. An attacker could exploit this to: * Bypass proxy-level ACL controls and WAF logic * Poison caches and upstream connections, causing subsequent requests from legitimate users to receive responses intended for smuggled requests * Perform cross-user attacks by hijacking sessions or smuggling requests that appear to originate from the trusted proxy IP Cloudflare's CDN infrastructure was not affected by this vulnerability, as ingress proxies in the CDN stack maintain proper HTTP parsing boundaries and do not prematurely switch to upgraded connection forwarding mode. Mitigation: Pingora users should upgrade to Pingora v0.8.0 or higher As a workaround, users may return an error on requests with the Upgrade header present in their request filter logic in order to stop processing bytes beyond the request header and disable downstream connection reuse.CVE-2026-1229chainguardaactl+6247mo ago24-02-2026 07:58

The CombinedMult function in the CIRCL ecc/p384 package (secp384r1 curve) produces an incorrect value for specific inputs. The issue is fixed by using complete addition formulas. ECDH and ECDSA signing relying on this curve are not affected. The bug was fixed in v1.6.3 https://github.com/cloudflare/circl/releases/tag/v1.6.3 .CVE-2026-11325cloudflarehttps://github.com/cloudflare/pages-action2mo ago12-08-2026 11:31

Description Cloudflare was recently notified by external researchers of vulnerabilities in this archived repository, including a remote code execution issue in `src/index.ts` reachable from certain GitHub Actions workflow configurations. Successful exploitation may expose workflow secrets such as CLOUDFLARE_API_TOKEN and GITHUB_TOKEN to an attacker. Because this repository has been deprecated since 2024, Cloudflare will not be issuing patches. To remediate this issue, we recommend migrating to `cloudflare/wrangler-action` immediately. Consumers who have already migrated are not affected. Sunset Date The cloudflare/pages-action repository will be removed on 2026-09-18. Consumers must complete migration before 18th September to avoid CI disruption. Affected Versions All published versions of cloudflare/pages-action, including consumers pinned to the v1 moving tag. Patched Versions None. This repository will not receive further updates, including security patches. Resolution / Migration Path Migrate all workflows using cloudflare/pages-action to `cloudflare/wrangler-action` before 2026-09-18. Refer to the wrangler-action README for the equivalent step configuration and migration guidance. Credit Thanks to @agentka99 and @beg1nn3r for reporting their findings via Cloudflare's HackerOne program that informe CVE-2026-11941Crates.Ioquiche+14mo ago19-06-2026 09:55

Cloudflare Quiche was affected by 2 use-after-free vulnerabilities in the connection ID iterator FFI functions. The “quiche_connection_id_iter_next” and “quiche_conn_retired_scid_next” functions would return a pointer to a “ConnectionId” to the applications via function arguments, but the owned “ConnectionId” would be dropped at the end of those functions' scope. Only applications using those FFI functions are affected. The FFI API is disabled by default by a build-time feature flag. Impact If unpatched, an application calling the affected FFI functions will dereference freed memory. The most likely outcome is undefined behavior leading to a process crash (denial of service). Depending on allocator state, the read may also return adjacent heap contents, resulting in limited information disclosure or incorrect connection identifier handling. Mitigation Users are requested to upgrade to quiche 0.29.2 which is the earliest version containing the fix for this issue.CVE-2026-0933cloudflarewrangler+19mo ago20-01-2026 22:58

SummaryA command injection vulnerability (CWE-78) has been found to exist in the `wrangler pages deploy` command. The issue occurs because the `--commit-hash` parameter is passed directly to a shell command without proper validation or sanitization, allowing an attacker with control of `--commit-hash` to execute arbitrary commands on the system running Wrangler. Root causeThe commitHash variable, derived from user input via the --commit-hash CLI argument, is interpolated directly into a shell command using template literals (e.g., execSync(`git show -s --format=%B ${commitHash}`)). Shell metacharacters are interpreted by the shell, enabling command execution. ImpactThis vulnerability is generally hard to exploit, as it requires --commit-hash to be attacker controlled. The vulnerability primarily affects CI/CD environments where `wrangler pages deploy` is used in automated pipelines and the --commit-hash parameter is populated from external, potentially untrusted sources. An attacker could exploit this to: * Run any shell command. * Exfiltrate environment variables. * Compromise the CI runner to install backdoors or modify build artifacts. Credits Disclosed responsibly by kny4hacker. Mitigation * Wrangler v4 users are requested to upgrade to Wrangler v4.59.1 or higher. * Wrangler v3 users are requested to upgrade to Wrangler v3.114.17 or higher. * Users on Wrangler v2 (EOL) should upgrade to a supported major version.CVE-2026-14440cloudflareuniversal ssl3mo ago01-07-2026 22:35

Description: To issue and renew TLS certificates on behalf of customers, Cloudflare's Universal SSL feature automatically manages the CAA RRset for the customer's zone. This auto-managed RRset is permissive by design (e.g. 'issue "letsencrypt.org"' without parameters). On Universal SSL zones, Cloudflare's authoritative DNS serves this auto-managed RRset at query time, superseding any customer-configured CAA records on the zone. When a customer publishes a stricter CAA record using the RFC 8657 accounturi or validationmethods parameters, the Certificate Authority does not observe those parameters when evaluating the served RRset under RFC 8659. As a result, the RFC 8657 account-binding and validation-method-binding protections are not enforced end-to-end on Universal SSL zones. Successful exploitation could result in issuance of a browser-trusted TLS certificate to an attacker, enabling MITM against the affected domain. Exploitation is non-trivial in practice: an attacker would need to hold an ACME account at one of the Certificate Authorities in the served CAA RRset and to simultaneously satisfy domain control validation across the multiple geographically distinct Network Perspectives the CA relies on for Multi-Perspective Issuance Corroboration. Cloudflare prefixes are anycast-announced from hundreds of locations globally, raising the bar against single-vantage-point BGP hijacks. Any resulting misissuance of a browser-trusted certificate is subject to Certificate Transparency logging required by major browsers, and would be visible to CT monitoring. Mitigation: Customers requiring strict RFC 8657 enforcement need to disable Universal SSL on the affected zone. Universal SSL's automatic CAA management and customer-set RFC 8657 accounturi and validationmethods enforcement are mutually exclusive by the nature of the issue, so there is no in-product workaround that preserves both. Certificate Transparency monitoring is recommended for all customers as a general detection control. Credits: David Osipov (ORCID: https://orcid.org/0009-0005-2713-9242), independent researcher CVE-2026-12707cloudflarequiche3mo ago14-07-2026 15:18

Summary Cloudflare quiche was discovered to be vulnerable to memory resource exhaustion due to unbounded queuing of post-handshake client migration events. Impact quiche supports the connection migration features described in Section 9 of RFC 9000, which allows a single QUIC connection to survive changes in the network path. Although quiche implements the protections described in Section 9.3 of RFC 9000 to limit server state commitment, it was discovered that the collection of PathEvents, intended to be consumed by applications via the path_event_next() function, was not bounded. Once the QUIC handshake completed, a peer could exploit rapid source address migration in order to cause unbounded queuing of the PathEvent::ReusedSourceConnectionId type. Servers are vulnerable even if active connection migration is disabled. Mitigation: * Applications can call path_event_next() to drain the PathEvent collection, mitigating the attack. * Users are requested to upgrade to quiche 0.29.3 which is the earliest version that prevents excessive queueing of PathEvent::ReusedSourceConnectionId.CVE-2026-12523cloudflarequiche3mo ago14-07-2026 15:51

Summary Cloudflare quiche's HTTP/3 layer was discovered to be vulnerable to resource exhaustion (i.e., memory) by means of specially crafted HTTP/3 frames. Impact HTTP/3 defines multiple frame types to support HTTP message exchanges and connection management. Each frame has a length and a payload whose length depends on the frame type. quiche was found to be vulnerable when parsing some frame types to pre-allocating memory based on the declared length. An attacker would not need to send the number of declared bytes to trigger this issue. In addition, quiche was found to not apply QPACK decompression limits correctly. This could allow an attacker to send specially crafted HEADERS frames that would cause more memory commitment than otherwise advertised by MAX_FIELD_SECTION_SIZE (configured by set_max_field_section_size()). Mitigation: * Users are requested to upgrade to quiche 0.29.3 which is the earliest version containing the fix for this issue. Credits: Disclosed responsibly by Sébastien Féry CVE-2023-2754cloudflarewarp3y ago03-08-2023 13:53

The Cloudflare WARP client for Windows assigns loopback IPv4 addresses for the DNS Servers, since WARP acts as local DNS server that performs DNS queries in a secure manner, however, if a user is connected to WARP over an IPv6-capable network, te WARP client did not assign loopback IPv6 addresses but Unique Local Addresses, which under certain conditions could point towards unknown devices in the same local network which enables an Attacker to view DNS queries made by the device.CVE-2023-2512cloudflareworkerd+13y ago12-05-2023 10:09

Prior to version v1.20230419.0, the FormData API implementation was subject to an integer overflow. If a FormData instance contained more than 2^31 elements, the forEach() method could end up reading from the wrong location in memory while iterating over elements. This would most likely lead to a segmentation fault, but could theoretically allow arbitrary undefined behavior. In order for the bug to be exploitable, the process would need to be able to allocate 160GB of RAM. Due to this, the bug was never exploitable on the Cloudflare Workers platform, but could theoretically be exploitable on deployments of workerd running on machines with a huge amount of memory. Moreover, in order to be remotely exploited, an attacker would have to upload a single form-encoded HTTP request of at least tens of gigabytes in size. The application code would then have to use request.formData() to parse the request and formData.forEach() to iterate over this data. Due to these limitations, the exploitation likelihood was considered Low. A fix that addresses this vulnerability has been released in version v1.20230419.0 and users are encouraged to update to the latest version available.CVE-2023-1412cloudflarewarp3y ago05-04-2023 15:22

An unprivileged (non-admin) user can exploit an Improper Access Control vulnerability in the Cloudflare WARP Client for Windows (<= 2022.12.582.0) to perform privileged operations with SYSTEM context by working with a combination of opportunistic locks (oplock) and symbolic links (which can both be created by an unprivileged user). After installing the Cloudflare WARP Client (admin privileges required), an MSI-Installer is placed under C:\Windows\Installer. The vulnerability lies in the repair function of this MSI. ImpactAn unprivileged (non-admin) user can exploit this vulnerability to perform privileged operations with SYSTEM context, including deleting arbitrary files and reading arbitrary file content. This can lead to a variety of attacks, including the manipulation of system files and privilege escalation. PatchesA new installer with a fix that addresses this vulnerability was released in version 2023.3.381.0. While the WARP Client itself is not vulnerable (only the installer), users are encouraged to upgrade to the latest version and delete any older installers present in their systems.CVE-2023-1732chainguardaactl+53y ago10-05-2023 11:41

When sampling randomness for a shared secret, the implementation of Kyber and FrodoKEM, did not check whether crypto/rand.Read() returns an error. In rare deployment cases (error thrown by the Read() function), this could lead to a predictable shared secret. The tkn20 and blindrsa components did not check whether enough randomness was returned from the user provided randomness source. Typically the user provides crypto/rand.Reader, which in the vast majority of cases will always return the right number random bytes. In the cases where it does not, or the user provides a source that does not, the blinding for blindrsa is weak and integrity of the plaintext is not ensured in tkn20.CVE-2023-1862cloudflarewarp+13y ago20-06-2023 08:28

Cloudflare WARP client for Windows (up to v2023.3.381.0) allowed a malicious actor to remotely access the warp-svc.exe binary due to an insufficient access control policy on an IPC Named Pipe. This would have enabled an attacker to trigger WARP connect and disconnect commands, as well as obtaining network diagnostics and application configuration from the target's device. It is important to note that in order to exploit this, a set of requirements would need to be met, such as the target's device must've been reachable on port 445, allowed authentication with NULL sessions or otherwise having knowledge of the target's credentials.CVE-2023-1314cloudflarecloudflared+13y ago21-03-2023 11:01

A vulnerability has been discovered in cloudflared's installer (<= 2023.3.0) for Windows 32-bits devices that allows a local attacker with no administrative permissions to escalate their privileges on the affected device. This vulnerability exists because the MSI installer used by cloudflared relied on a world-writable directory. An attacker with local access to the device (without Administrator rights) can use symbolic links to trick the MSI installer into deleting files in locations that the attacker would otherwise have no access to. By creating a symlink from the world-writable directory to the target file, the attacker can manipulate the MSI installer's repair functionality to delete the target file during the repair process. Exploitation of this vulnerability could allow an attacker to delete important system files or replace them with malicious files, potentially leading to the affected device being compromised. The cloudflared client itself is not affected by this vulnerability, only the installer for 32-bit Windows devices.CVE-2023-0238cloudflarewarp+13y ago29-08-2023 14:56

Due to lack of a security policy, the WARP Mobile Client (<=6.29) for Android was susceptible to this vulnerability which allowed a malicious app installed on a victim's device to exploit a peculiarity in an Android function, wherein under certain conditions, the malicious app could dictate the task behaviour of the WARP app.CVE-2023-0654cloudflarewarp+13y ago29-08-2023 15:05

Due to a misconfiguration, the WARP Mobile Client (< 6.29) for Android was susceptible to a tapjacking attack. In the event that an attacker built a malicious application and managed to install it on a victim's device, the attacker would be able to trick the user into believing that the app shown on the screen was the WARP client when in reality it was the attacker's app.CVE-2023-0652cloudflarewarp3y ago06-04-2023 09:42

Due to a hardlink created in the ProgramData folder during the repair process of the software, the installer (MSI) of WARP Client for Windows (<= 2022.12.582.0) allowed a malicious attacker to forge the destination of the hardlink and escalate privileges, overwriting SYSTEM protected files. As Cloudflare WARP client for Windows (up to version 2022.5.309.0) allowed creation of mount points from its ProgramData folder, during installation of the WARP client, it was possible to escalate privileges and overwrite SYSTEM protected files.CVE-2023-4241Crates.Iolol-html+13y ago16-08-2023 10:13

lol-html can cause panics on certain HTML inputs. Anyone processing arbitrary 3rd party HTML with the library is affected.CVE-2023-7078cloudflareminiflare+12y ago29-12-2023 11:53

Sending specially crafted HTTP requests to Miniflare's server could result in arbitrary HTTP and WebSocket requests being sent from the server. If Miniflare was configured to listen on external network interfaces (as was the default in wrangler until 3.19.0), an attacker on the local network could access other local servers.