Use-after-free in S/MIME decryption during a security device password prompt

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-113869
StatePUBLISHED
Assignermozilla
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-20 20:17:19 UTC
Updated2026-10-20 20:17:19 UTC
DescriptionWhen Thunderbird asked for a security device password (for example a smartcard PIN or the Primary Password) while decrypting an S/MIME message, the message load could finish or be cancelled while the prompt was open. This freed the message decoder while it was still in use, causing a use-after-free and a potentially exploitable crash. This vulnerability was fixed in Thunderbird 158.0.1.

Risk And Classification

Primary CVSS: v3.1 5.4 MEDIUM from ADP

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L

Problem Types: CWE-416 | CWE-416 CWE-416 Use After Free

VersionSourceTypeScoreSeverityVector
3.1ADPDECLARED5.4MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L
3.1134c704f-9b21-4f2e-91b3-4a467353bcc0Secondary5.4MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Mozilla Thunderbird unaffected 158.0.1 * rpm Not specified

References

ReferenceSourceLinkTags
www.mozilla.org/security/advisories/mfsa2026-114 [email protected] www.mozilla.org
bugzilla.mozilla.org/show_bug.cgi [email protected] bugzilla.mozilla.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Stefan Tatschner (en)

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