CVE-2026-110247
Several buffer-growth sites in libmime performed size arithmetic in 32-bit types without overflow…
- Risk score
- 51/100
- CVSS
- 8.4 v3.1
- Exploit chance (30 days)
- 0.2%
- Published
- 13 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- 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 al…
- Affected
- See advisory
- Fix
- Apply the vendor's security update; see the linked advisory.
- Exploitation
- No known exploitation
Why it is Yellow
- CVSS 8.4 high
References
Original description
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.
Last activity 13 Oct 2026. Patch Forecast updates every hour.