CVE-2026-110247Integer overflow in libmime buffer growth could lead to heap corruption
Updated under an hour ago ()
Does this affect you?
It affects Mozilla Thunderbird. Add what you run to find out whether that includes you.
EPSS puts the chance of exploitation in the next 30 days at 0.17%, higher than 7% of scored CVEs.
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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.
- CVSS
- 8.4 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-190
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- 0.17% (percentile 7)
- Assigned by
- mozilla
- NVD analysis
- Awaiting Analysis
- Record last updated
- Oct 21, 2026
- First seen by InfoSec Signals
- Oct 13, 2026
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.