High [CVE-2026-42959] Unbound DNSSEC Validator Denial of Service via Incorrect Write Offset Counter in Chase-Reply Messages
This high-severity Red Hat Linux advisory covers CVE-2026-42959 affecting Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9.
Android app · Google Play
Monitor future Red Hat Linux CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 32 official vendor sources and 160+ reviewed platform categories.
Summary
Unbound DNSSEC Validator Denial of Service via Incorrect Write Offset Counter in Chase-Reply Messages. Red Hat rates this important (CVSS 7.5).
Weakness: CWE-824. Affected package(s): unbound-main, unbound.
Resolved in Red Hat advisory RHSA-2026:23231 — update the affected packages (`sudo dnf update`).
Affected products named by the advisory: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9; Red Hat Hardened Images; and 2 more.
- unbound-main-1.25.1-0.1.hum1
- unbound-0:1.16.2-5.11.el8_10
- unbound-0:1.24.2-7.el10_2.1
- unbound-0:1.24.2-3.el9_8.1
Official advisory · high-confidence parse· fetched 2 months ago·verify at source
- RHSA-2026:23231
Official advisory · high-confidence parse· fetched 2 months ago·verify at source
Mitigation checklist
- Update the affected package(s) to the fixed version shipped in RHSA-2026:23231 (`sudo dnf update` / `yum update`).
Official advisory · high-confidence parse· fetched 2 months ago·verify at source
Discussion(0)
No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.
Sign in to join the discussion.