CVE-2026-113867 Affecting thunderbird package, versions <1:153.5.1esr-1~deb13u1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.4% (35th percentile)

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  • Snyk IDSNYK-DEBIAN13-THUNDERBIRD-21404782
  • published22 Oct 2026
  • disclosed20 Oct 2026

Introduced: 20 Oct 2026

NewCVE-2026-113867  (opens in a new tab)

How to fix?

Upgrade Debian:13 thunderbird to version 1:153.5.1esr-1~deb13u1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream thunderbird package and not the thunderbird package as distributed by Debian. See How to fix? for Debian:13 relevant fixed versions and status.

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 Base Scores

version 3.1