CVE-2026-19499
Published: August 27, 2026Last modified: September 4, 2026
Description
Calling strfmon and strfmon_l in the GNU C Library version 2.38 to 2.44 can write past the end of the caller-supplied output buffer when a conversion uses right-justified width padding. Exploitation requires an application code path that calls strfmon or strfmon_l with right-justified width padding into a destination buffer that is large enough for the padding to succeed but too small for the internal memmove call. The field width or format may be attacker-influenced or a fixed susceptible pattern in the caller. At the time of publication, no network-facing application impact is known.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.7 |
| Attack Vector | NETWORK |
| Attack complexity | HIGH |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | LOW |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | glibc | Fixed (2.37.0-r26) |
| 25 LTS | glibc | Fixed (2.39.0-r12) | |
| Stream | glibc | Fixed (2.43.0-r6) | |
| Hardened Containers | 23 LTS | glibc | Fixed (2.37.0-r26) |
| 25 LTS | glibc | Fixed (2.39.0-r12) | |
| Stream | glibc | Fixed (2.43.0-r6) |