CVE-2026-115778
Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.10.0rc1, twisted.conch.telnet.Telnet.dataReceived appends every byte received after IAC SB to a persistent subnegotiation buffer until IAC SE is received, without applying a maximum length. Telnet option negotiation occurs before authentication, so an unauthenticated peer can omit the terminator and continuously grow the buffer. The resulting memory exhaustion can terminate the process and every service it hosts. This issue is fixed in version 26.10.0rc1.
- CVSS 3.1
- 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS
- 0.5% chance of exploitation in the next 30 days; higher than 45% of CVEs (scores of 2026-10-25)
- CWEs
- CWE-400, CWE-770
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-cwm5-jh59-mwxr | PyPI | twisted | <26.10.0rc1 | 26.10.0rc1 |
References
- https://github.com/twisted/twisted/commit/073ba878c6c07d569cb61abc5ae76d46eff1b529
- https://github.com/twisted/twisted/commit/5d91cc66a3591faba758a80a1479e0103602facc
- https://github.com/twisted/twisted/pull/12750
- https://github.com/twisted/twisted/releases/tag/twisted-26.10.0rc1
- https://github.com/twisted/twisted/security/advisories/GHSA-cwm5-jh59-mwxr