CVE-2026-113867

Stanza injection in XMPP chat

State
Published
Severity
9.1 Critical
Published
Oct 20, 2026
Updated
Oct 29, 2026
Reserved
Oct 20, 2026

Read the record on cve.org

Description

Thunderbird did not escape attribute values when serializing outgoing XMPP stanzas. Because values from incoming requests were echoed back in automatic replies, a remote XMPP user could send a crafted request that caused Thunderbird to inject arbitrary stanzas into the user's connection, which the server would then process as if sent by the user. This could be used to send messages or change contact and subscription settings on behalf of the user, without any interaction. This bug only affects Thunderbird's chat feature with XMPP accounts. This vulnerability was fixed in Thunderbird 158.0.1 and Thunderbird 153.5.1.

Scores

CVSSScoreVectorSource
3.19.1 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NCISA-ADP

Weaknesses

  • CWE-116 Improper Encoding or Escaping of Output

Affected Products

ProductVersions
ThunderbirdMozilla
  • 153.5.1 through 153.*Not affected
  • 158.0.1 and laterNot affected

References

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