Prior to 26.10.0rc1, twisted.conch.telnet.Telnet.dataReceived appends every byte received after IAC SB to a persistent
Affects twistedSource GCVE Database
Not known to be exploited · CVSS 7.5 High · fixed in 26.10.0 : patch twisted soon.
Data as of 28 Oct 2026, 22:44 UTC
- Patch
- Available – fixed in 26.10.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 23 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10twistedpkg:deb/ubuntu/twisted?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTStwistedpkg:deb/ubuntu/twisted?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTStwistedpkg:deb/ubuntu/twisted?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTStwistedpkg:deb/ubuntu/twisted?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 20.04 LTStwistedpkg:deb/ubuntu/twisted?arch=source&distro=focalOther threats | Affected
| Fixed in– |
Ubuntu Pro 18.04 LTStwistedpkg:deb/ubuntu/twisted?arch=source&distro=esm-infra/bionicOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade Twisted to version 26.10.0rc1 or later, where this vulnerability is fixed. No other mitigation or workaround is indicated.
Description
A vulnerability in Twisted prior to version 26.10.0rc1 allows an unauthenticated attacker to cause memory exhaustion by exploiting the Telnet subnegotiation buffer. The Telnet.dataReceived method appends every byte received after the IAC SB command to a persistent buffer without a maximum length until the IAC SE terminator is received. Since Telnet option negotiation happens before authentication, an attacker can omit the terminator and cause continuous buffer growth, leading to process termination.
References
- ubuntu.com/security/CVE-2026-115778 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-115778 (opens in a new tab)
- github.com/twisted/twisted/commit/073ba878c6c07d569cb61abc5ae76d46eff1b529 (opens in a new tab)
- github.com/twisted/twisted/commit/5d91cc66a3591faba758a80a1479e0103602facc (opens in a new tab)
- github.com/twisted/twisted/pull/12750 (opens in a new tab)
- github.com/twisted/twisted/releases/tag/twisted-26.10.0rc1 (opens in a new tab)
- github.com/twisted/twisted/security/advisories/GHSA-cwm5-jh59-mwxr (opens in a new tab)