CVE-2026-56099

EUVD-2026-37938
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
5.3 MEDIUM
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 34%
Affected Products (NVD)
VendorProductVersion
openbsdopenbsd
𝑥
< 2026-06-18
𝑥
= Vulnerable software versions
Common Weakness Enumeration
References
https://github.com/openbsd/src/commit/6a23123ec05f1eb29cfcaae0f3a468b2e1983cfd
https://pop.argus-systems.ai/advisory/adv-040.html
https://www.vulncheck.com/advisories/openbsd-mpls-do-error-kernel-stack-memory-disclosure-via-mpls-input
http://seclists.org/fulldisclosure/2026/Jun/17
http://www.openwall.com/lists/oss-security/2026/06/19/3