CVE-2026-115776: Twisted: Unauthenticated Remote Denial of Service in the Twisted IRC Server via an Unbounded Line Buffer
Vulnerability summary
CVE-2026-115776 is a high (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in twisted. EPSS estimates a 0.50% chance of exploitation in the next 30 days, higher than 42.9% of scored vulnerabilities.
Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 1 · Related 1Timeline
- 23-10-2026PublishedVulnerability first disclosed.
- 30-10-2026Last modifiedVulnerability information updated.
Description
Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.10.0rc1, twisted.words.protocols.irc.IRC.dataReceived retains all bytes received without a line feed in its per-connection buffer and applies no maximum line length. The twisted.words.service.IRCUser server subclass inherits this behavior, and buffering occurs before PASS, NICK, or USER authentication commands. An unauthenticated connection can continuously grow the buffer until the shared server process runs out of memory and drops all users. This issue is fixed in version 26.10.0rc1.
CVSS metrics
6 scores · 6 sources · 1 version- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · PypiEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · ChainguardEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.50%
Chance of exploitation in the next 30 days
Percentile
43%
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
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-400Uncontrolled Resource ConsumptionThe product does not properly control the allocation and maintenance of a limited resource.
- CWE-770Allocation of Resources Without Limits or ThrottlingThe product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
Affected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Chainguard2 products
- awxAll versions (No fix recorded)
- synapseAll versions (No fix recorded)
Debian1 product
- twistedAll versions (No fix recorded) | < 26.10.0-1
PyPI1 product
- twisted< 26.10.0rc1
Twisted1 product
- twisted< 26.10.0rc1
Ubuntu1 product
- twistedAll versions (No fix recorded)
5 vendors · 6 products
References
11 links- github.com/twisted/twisted/security/advisories/GHSA-53xc-49m8-p798X Refsource CONFIRMWEBAdvisoryREPORT
- github.com/twisted/twisted/commit/01f8cff7753c1edac132380b2ea939fa6bdbab30X Refsource MISCWEBFIXREPORT
- github.com/twisted/twisted/commit/ac90fb7b0ab73688a581fcd9a7c0577ec8ca3059X Refsource MISCWEBFIXREPORT
- github.com/twisted/twistedPACKAGE
