9.1
Critical
CVE-2026-113867 Thunderbird did not escape attribute values when serializing outgoing XMPP stanzas
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.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Thunderbird 158.0 | earliest → < 158.0.1 | 158.0.1 |
| Thunderbird 153.5 | earliest → < 153.5.1 | 153.5.1 |
References
- bugzilla.mozilla.org bugzilla.mozilla.org
- www.mozilla.org www.mozilla.org
- www.mozilla.org www.mozilla.org
Timeline
- Published
- Last modified
Other CVEs of Thunderbird
The 1713 CVEs of Thunderbird →
CVE-2026-118180
Matrix homeserver could redirect the chat session to a local file or network share
7.5
High
CVE-2026-118179
Request forgery via news: links
8.8
High
CVE-2026-118178
RSS feed could redirect its subscription to a local file or network share
5.7
Medium
CVE-2026-118177
Calendar discovery accepted local file and remote network share locations
9.1
Critical