Thunderbird did not escape attribute values when serializing outgoing XMPP stanzas
Mozilla · Thunderbird
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.
- Exploited
- Not confirmed
- Reports
- 0
- Tactics
- 0/15
Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
Disclosed on 20 Oct 2026. No public exploit code or confirmed exploitation is recorded.
MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. techniques
No techniques linkedNo ATT&CK techniques are linked to this CVE yet. MITRE CTID has not mapped it, and no report passage in the corpus ties it to a technique.
What security researchers reported
Not named in any threat report yetAlso mentioned in 6 community threat pulses (AlienVault OTX)
Weaker evidencePulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.
- Known_Cve | Oct 29, 2026 | Part 1/328 Oct 2026
- Known_Cve | Oct 28, 2026 | Part 1/327 Oct 2026
- Known_Cve | Oct 27, 2026 | Part 1/326 Oct 2026
- Known_Cve | Oct 24, 2026 | Part 2/323 Oct 2026
- Known_Cve | Oct 23, 2026 | Part 2/322 Oct 2026
- Known_Cve | Oct 22, 2026 | Part 3/421 Oct 2026