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GLIBC-SA-2026-0011 on CTRL-OS 26.05

Aliases: GLIBC-SA-2026-0011, CVE-2026-5435

Packages: glibc

Status: In Progress

Advisory Information

The deprecated functions ns_printrrf, ns_printrr and fp_nquery in the
GNU C Library version 2.2 and newer fail to enforce the caller-supplied
buffer length, and can result in an out-of-bounds write when printing
TSIG records.

A defect in the TSIG case handling within ns_sprintrrf performs a
formatted write using sprintf without checking the remaining buffer
length, and may write up to 6 bytes past the end of the buffer.  If the
library is compiled with assertions, and the out-of-bounds write doesn't
terminate the process, then a subsequent check for "len <= *buflen" will
trigger an assertion failure.

These functions are for application debugging only and hence not in the
path of code executed by the DNS resolver. Further, they have been
deprecated since version 2.34 (2021-08-02) and should not be used by any
new applications.  Applications should consider porting away from these
interfaces since they may be removed in future versions.

CVE-Id: CVE-2026-5435
Public-Date: 2026-04-02
Vulnerable-Commit: b43b13ac2544b11f35be301d1589b51a8473e32b (2.2)
Reported-by: shinobu

Updates

2026-07-18 00:24 CEST

Metadata changes:

  • Status for package glibc: “In Progress” (f48798d58d89c52ac06cd3880ad9b91a0f90a5b2)

2026-07-01 10:55 CEST

Comment:

Proposed fix in Nixpkgs unstable: https://github.com/NixOS/nixpkgs/pull/537324

2026-06-30 15:37 CEST

Metadata changes:

  • Status for package glibc: “Plausible”

Comment:

Fixed in 2.44, backporting status unclear.

2026-05-28 23:40 CEST

Metadata changes:

  • Status for package glibc: “New”