CVE-2026-19499
Publication date 27 August 2026
Last updated 16 September 2026
Ubuntu priority
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| glibc | 26.04 LTS resolute |
Fixed 2.43-2ubuntu2.4
|
| 24.04 LTS noble |
Fixed 2.39-0ubuntu8.9
|
|
| 22.04 LTS jammy |
Not affected
|
|
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial |
Not affected
|
|
| eglibc | 26.04 LTS resolute | Not in release |
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy | Not in release | |
| 14.04 LTS trusty |
Not affected
|
Notes
mdeslaur
introduced in 2.37 by: https://sourceware.org/git?p=glibc.git;a=object;h=e88b9f0e5cc50cab57a299dc7efe1a4eb385161d
Patch details
| Package | Patch details |
|---|---|
| glibc |
Severity score breakdown
CVSS version: CVSS v3.0
Base score
7.7 · High
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:H
References
Related Ubuntu Security Notices (USN)
- USN-8737-1
- GNU C Library vulnerabilities
- 8 September 2026
- USN-8737-2
- GNU C Library vulnerabilities
- 10 September 2026