Vulnerability details

CVE-2026-113867

Stanza injection in XMPP chat

CVSS 3.1
9.1Critical

Official 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.

CVSS scores

ScoreVersionSourceVector
9.1Critical 3.1 CISA ADP / Vulnrichment (CISA-ADP) CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected products

VendorProductVersionsSource
No product information recorded.

References and advisories

3
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Details

Published
2026-10-20
Last updated
2026-10-29
State
Published
Assigner (CNA)
mozilla
Kolun priority
22 · Low

Exploit prediction (EPSS)

0.39%
Probability of exploitation in 30 days
34.3%
Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable
Yes
Exploitation
None
Technical impact
Total

Weaknesses (CWE)

  • CWE-116
    Improper Encoding or Escaping of Output