CVE-2026-5450CWE-122
scanf %mc off-by-one heap buffer overflow
Critical · published April 20, 2026
What it is
Calling the scanf family of functions with a %mc (malloc'd character match) in the GNU C Library version 2.7 to version 2.43 with a format width specifier with an explicit width greater than 1024 could result in a one byte heap buffer overflow.
The record
Technical detail
- CVSS v3.1
- 9.8 · CRITICAL
- Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CVSS v4.0
- Not supplied
- EPSS
- 0.00718 · 53.4th percentile
- Weakness
- CWE-122 · Heap-based Buffer Overflow
- Published
- 2026-04-20T20:55Z
EPSS history
Timeline