Description
OpenBSD before commit 6a23123 (2026-06-18) contains an out-of-bounds read vulnerability in the mpls_do_error function within sys/netmpls/mpls_input.c that allows remote attackers to disclose kernel stack memory by sending crafted MPLS frames with 16 labels and no Bottom-of-Stack bit set.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| openbsd | src | — | — |
Advisories 1
- WID-SEC-2026-2003 OpenBSD: Schwachstelle ermöglicht Offenlegung von Informationen BSI CERT-Bund (WID) · Jun 18, 2026
References
- https://pop.argus-systems.ai/advisory/adv-040.html technical-description exploit
- https://github.com/openbsd/src/commit/6a23123ec05f1eb29cfcaae0f3a468b2e1983cfd patch
- https://www.vulncheck.com/advisories/openbsd-mpls-do-error-kernel-stack-memory-disclosure-via-mpls-input third-party-advisory