CVE-2026-113867

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 v3 9.1 CRITICAL

9.1^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://bugzilla.mozilla.org/show_bug.cgi?id=2080073
https://www.mozilla.org/security/advisories/mfsa2026-114/
https://www.mozilla.org/security/advisories/mfsa2026-115/

Configurations

No configuration.

History

29 Oct 2026, 19:17

Type	Values Removed	Values Added
CWE		CWE-116
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 9.1

20 Oct 2026, 20:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-20 20:17

Updated : 2026-10-29 19:17

NVD link : CVE-2026-113867

Mitre link : CVE-2026-113867

CVE.ORG link : CVE-2026-113867

JSON object : View

Products Affected

No product.

CWE

CWE-116

Improper Encoding or Escaping of Output

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