Patch Forecast
Amber warning
Patch this week.

CVE-2026-115776 · GHSA-53xc-49m8-p798

Twisted: Unauthenticated Remote Denial of Service in the Twisted IRC Server via an Unbounded Line Buffer

Risk score
66/100
CVSS
7.5 v3.1
Exploit chance (30 days)
0.7%
Published
23 Oct 2026

Open in the live forecast Today's forecast

What to know

What it is
A vulnerability in Twisted's IRC server allows an unauthenticated remote denial of service via an unbounded line buffer. An attacker could continuously grow the buffer until the server runs out of memory.
Affected
{'products': ['Twisted'], 'packages': ['Twisted'], 'versions': ['<= 26.4.0']}
Fix
Upgrade to version 26.10.0rc1 or later
Exploitation
No known exploitation

Story map

Story map: TwistedTHE FLAWSTHE FIXCVE-2026-115776Unauthenticated Remote Denialof Service in the Twisted IRCServer via an Unbounded Line…CVSS 7.5 · EPSS 1%CVE-2026-115775Unauthenticated Remote Denialof Service in the Twistedwords domish XML Element…CVSS 8.7 · EPSS 1%CVE-2026-115778Unauthenticated Remote Denialof Service in the Twisted conchTelnet Transport via an…CVSS 7.5 · EPSS 1%CVE-2026-115774Denial of Service in theTwisted IMAP4 Server via aNegative Literal Size in…CVSS 4.9 · EPSS 1%Upgrade Twisted26.10.0or later on your release lineWho is exposed{'products': ['Twisted'],'packages': ['Twisted'],'versions': ['<= 26.4.0']}AMBER · PATCH THIS WEEKTwistedTwisted has a vulnerability in itsXML parser that allows anunauthenticated remote peer tocause a denial of service bycontinuously adding childelements to an in-memory tree,exhausting server memory and…Where it standsNo known exploitationCONNECTS TOSame weaknessDenial of service (CWE-400)250 other warnings in 30 days →
Story map: the flaws, the fix, how it unfolded and what it connects to. Boxes link to the record or article.

At a glance

Twisted: Amber, patch this week. Twisted has a vulnerability in its XML parser that allows an unauthenticated remote peer to cause a denial of service by continuously adding child elements to an in-memory tree, exhausting server memory and terminating the process.

The flaws

  • CVE-2026-115776: Unauthenticated Remote Denial of Service in the Twisted IRC Server via an Unbounded Line Buffer (CVSS 7.5 · EPSS 1%)
  • CVE-2026-115775: Unauthenticated Remote Denial of Service in the Twisted words domish XML Element Stream via an Unbounded Element Tree (CVSS 8.7 · EPSS 1%)
  • CVE-2026-115778: Unauthenticated Remote Denial of Service in the Twisted conch Telnet Transport via an Unbounded Subnegotiation Buffer (CVSS 7.5 · EPSS 1%)
  • CVE-2026-115774: Denial of Service in the Twisted IMAP4 Server via a Negative Literal Size in SEARCH (CVSS 4.9 · EPSS 1%)

The fix

Upgrade Twisted: 26.10.0 or later on your release line

Who is exposed: {'products': ['Twisted'], 'packages': ['Twisted'], 'versions': ['<= 26.4.0']}

Where it stands

  • No known exploitation

Connects to

Why it is Amber

  • CVSS 7.5 high
  • Remotely exploitable without logging in
  • On your watchlist: PyPI

Affected packages

PackageEcosystemVulnerableFixed in
Twistedpip<= 26.4.026.10.0rc1

References

Original 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.

Last activity 23 Oct 2026. Patch Forecast updates every hour.