CVE-2026-113869: Use-after-free in S/MIME decryption during a security device password prompt

Awaiting analysis

AliasesUBUNTU-CVE-2026-113869

Published 20-10-2026Last modified 27-10-2026

Vulnerability summary

CVE-2026-113869 is a medium (CVSS 5.4) Use After Free vulnerability in thunderbird Ubuntu. EPSS estimates a 0.33% chance of exploitation in the next 30 days, higher than 26.2% of scored vulnerabilities.

Priority

Routine

Not severe (CVSS 5.4, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?

CVSS score

5.4/10

010

Medium · v3.1 (CVE.org)

EPSS score

0.33%

0%100%

Low · Change unavailable

KEVNot listedNot listed by any tracked catalog.

RansomwareNot flaggedNo ransomware use recorded.

Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1 · Related 1

OPENSUSE-SU-2026:12339-1

Timeline

20-10-2026
PublishedVulnerability first disclosed.
27-10-2026
Last modifiedVulnerability information updated.

Description

When 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 and Thunderbird 153.6.

CVSS metrics

3 scores · 3 sources · 1 version

v3.15.4

EPSS trend

Probability

0.33%

Chance of exploitation in the next 30 days

Percentile

26%

Versus all other CVEs

30-day change

Change unavailable

21-10-202603-11-2026

Known exploited

Compare KEV catalogs

CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected systems

Version check

Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu1 product

thunderbirdAll versions (No fix recorded)

1 vendor · 1 product

References

6 links