What’s Vulnerable › Vulnerabilities

CVE-2026-115775: Twisted: Unauthenticated Remote Denial of Service in the Twisted words domish XML Element Stream via an Unbounded Element Tree

• Severity: high (CVSS 8.7 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-23 · updated 2026-10-29
• Weakness: CWE-400

Description

Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.10.0rc1, the twisted.words.xish.domish ExpatElementStream parser allows an unauthenticated remote peer to keep a container element open while continuously adding child elements. The parser retains the unfinished stanza as an in-memory tree without a byte or element-count limit, and XMPP pre-authentication stream parsing exposes this behavior before credentials are accepted. A single connection can therefore exhaust server memory and terminate the process. This issue is fixed in version 26.10.0rc1.

Affected products

• twisted: before 26.10.0rc1

References

• https://github.com/twisted/twisted/commit/8873814bec8288e2466fad4d2c4d64039beb88b0
• https://github.com/twisted/twisted/pull/12751
• https://github.com/twisted/twisted/releases/tag/twisted-26.10.0rc1
• https://github.com/twisted/twisted/security/advisories/GHSA-3476-c5c2-fr73
• https://github.com/twisted/twisted/security/advisories/GHSA-3476-c5c2-fr73

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