CVE Catalog

CVE-2026-110247

HighCVSS 8.4
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.18%

8th percentile - higher than 8% of all known CVEs

Summary

Several buffer-growth sites in libmime performed size arithmetic in 32-bit types without overflow checks. On a sufficiently large message the growth guard could fail open or the buffer could be reallocated smaller than required, and a subsequent memcpy would write attacker-controlled data across adjacent heap allocations.

Risk Assessment

This may lead to memory corruption and potential code execution when processing a crafted message.

Recommendation

Update Thunderbird to version 158 or 153.6, which contain the fix.

Related vulnerabilities

Original NVD description (English source)

Several buffer-growth sites in libmime performed size arithmetic in 32-bit types without overflow checks. On a sufficiently large message the growth guard could fail open, or the buffer could be reallocated smaller than required, and a subsequent memcpy would then write attacker-controlled data across adjacent heap allocations. This vulnerability was fixed in Thunderbird 158 and Thunderbird 153.6.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS