CVE-2026-107289: Pydantic AI: SSRF cloud-metadata blocklist bypass via IPv6 zone identifier (incomplete fix for CVE-2026-46678 and CVE-2026-48782)
Vulnerability summary
CVE-2026-107289 is a medium (CVSS 6.8) Server-Side Request Forgery vulnerability in pydantic pydantic_ai. EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 33.1% of scored vulnerabilities. 1 public exploit is recorded.
Not severe (CVSS 6.8, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Timeline
- 08-10-2026PublishedVulnerability first disclosed.
- 08-10-2026Last modifiedVulnerability information updated.
Description
Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 1.56.0 until 1.107.6 and 2.44.0, applications that opt attacker-influenced URLs into local network access through FileUrl with force_download='allow-local' or web_fetch_tool with allow_local_urls=True can bypass the cloud-metadata blocklist by appending an IPv6 zone identifier to an IPv6 metadata address. IPv6Address equality and hashing include the zone identifier, so the blocklist comparison fails even though the network stack ignores the zone on a non-link-local destination and reaches the metadata service, potentially exposing cloud IAM credentials. The opt-in settings are disabled by default, and the issue requires an IPv6-enabled environment. This issue is fixed in versions 1.107.6 and 2.44.0.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · PypiEcosystem advisory · calculated6.8MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
- NVDNIST6.8MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
EPSS trend
Probability
0.39%
Chance of exploitation in the next 30 days
Percentile
33%
Versus all other CVEs
30-day change
Change unavailable
Change unavailable
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
1 foundPydantic Ai
Maturity: poc
Weaknesses
CWE · root cause- CWE-918Server-Side Request ForgeryThe web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
- CWE-1289Improper Validation of Unsafe Equivalence in InputThe product receives an input value that is used as a resource identifier or other type of reference, but it does not validate or incorrectly validates that the input is equivalent to a potentially-unsafe value.
Affected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Pydantic3 products
- pydantic_ai≥ 1.56.0, < 1.107.6 | ≥ 2.0.0, < 2.44.0
- pydantic-ai≥ 1.56.0, < 1.107.6 | ≥ 2.0.0b1, < 2.44.0
- pydantic-ai-slim≥ 1.56.0, < 1.107.6 | ≥ 2.0.0b1, < 2.44.0
PyPI2 products
- pydantic-ai≥ 1.56.0, < 1.107.6 | ≥ 2.0.0b1, < 2.44.0
- pydantic-ai-slim≥ 1.56.0, < 1.107.6 | ≥ 2.0.0b1, < 2.44.0
2 vendors · 5 products
References
12 links- github.com/pydantic/pydantic-ai/security/advisories/GHSA-vmxc-h2x2-jmf3X Refsource CONFIRMWEBExploitMitigationVendor Advisory
- github.com/pydantic/pydantic-ai/commit/02157e1b87bd45d3f2e111ce07afdf89f9fb0e5bX Refsource MISCWEBExploitPatch
- github.com/pydantic/pydantic-ai/commit/4da70591460f51a8c4f128eaeef70a33340dbd55X Refsource MISCWEBExploitPatch
- github.com/pydantic/pydantic-ai/releases/tag/v1.107.6X Refsource MISCWEBPatchRelease NotesVendor Advisory
- github.com/pydantic/pydantic-ai/releases/tag/v2.44.0X Refsource MISCWEBPatchRelease NotesVendor Advisory
- pypi.org/project/pydantic-aiPACKAGE
