[PATCH] Add advisory text for CVE-2026-5435

[Siddhesh Poyarekar]

On 27/04/2026 17:52, Carlos O'Donell wrote:
> ---
>   advisories/GLIBC-SA-2026-0011 | 24 ++++++++++++++++++++++++
>   1 file changed, 24 insertions(+)
>   create mode 100644 advisories/GLIBC-SA-2026-0011

LGTM.

Reviewed-by: Siddhesh Poyarekar <siddhesh@gotplt.org>

> 
> diff --git a/advisories/GLIBC-SA-2026-0011 b/advisories/GLIBC-SA-2026-0011
> new file mode 100644
> index 0000000000..6c1e50fa74
> --- /dev/null
> +++ b/advisories/GLIBC-SA-2026-0011
> @@ -0,0 +1,24 @@
> +Potential buffer overflow in ns_sprintrrf TSIG handling path
> +
> +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 debugging only and hence not in the default 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