CVE-2026-56099

Medium

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.

SeverityMedium

CVSS5.3

Exploit probability—

ProductOpenbsd

PublishedJun 18, 2026

First seenJun 18, 2026

Weakness typeCWE-125Out-of-bounds read

How to fix

Update

openbsd openbsd2026-06-18 or later

Patches

github.com/openbsd/src/commit/6a23123ec05f1eb29cfcaae0f3a468b2e1983cfd

Affected products

Product	Affected versions	Fixed in
openbsd openbsd	v < 2026-06-18	2026-06-18

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