Is CVE-2026-113867 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-113867 being exploited in the wild.

How severe is CVE-2026-113867?

Informational severity, published 20 October 2026.

Which products and versions are affected?

Mozilla Thunderbird prior to 158.0.1 and 153.5.1.

Is there a fix for CVE-2026-113867?

Yes: fixed in Thunderbird 158.0.1, 153.5.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-113867 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-113867?

Check whether you run Mozilla Thunderbird at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-113867: Thunderbird XMPP stanza injection in chat

CVE-2026-113867 · Severity: info · Published 2026-10-20

Thunderbird's XMPP chat feature fails to properly escape attribute values when processing incoming messages, allowing a remote attacker to inject arbitrary stanzas into the user's connection. An attacker can send a crafted message that causes Thunderbird to execute commands on behalf of the user, such as sending messages or modifying contact settings, without any user interaction required.

Technologies: Mozilla Thunderbird. Vendors: Mozilla.

Quick answers

Is CVE-2026-113867 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-113867 being exploited in the wild.
How severe is CVE-2026-113867?: Informational severity, published 20 October 2026.
Which products and versions are affected?: Mozilla Thunderbird prior to 158.0.1 and 153.5.1.
Is there a fix for CVE-2026-113867?: Yes: fixed in Thunderbird 158.0.1, 153.5.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-113867 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-113867?: Check whether you run Mozilla Thunderbird at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: Thunderbird 158.0.1, 153.5.1

Technical details

Thunderbird's XMPP implementation does not escape attribute values when serializing outgoing stanzas; incoming request values are echoed back in automatic replies, enabling stanza injection. A remote XMPP user can craft a request that injects arbitrary stanzas processed by the server as legitimate user commands. This requires an active XMPP account and contact with the attacking user, but no user interaction.

Affected products

Mozilla Thunderbird prior to 158.0.1 and 153.5.1

Timeline

2026-10-20: disclosed
2026-10-20: patched

References

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