VulnerabilityAnalyzed
CVE-2026-56099
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…
MEDIUM 6.9EPSS 0.50%
Does this matter?
Lower severity and a low EPSS score (0.50%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 4.0
- 6.9 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.50% probability · 41th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-125
- Affected
- openbsd/openbsd
- Source
- disclosure@vulncheck.com
References
- https://github.com/openbsd/src/commit/6a23123ec05f1eb29cfcaae0f3a468b2e1983cfdPatch
- https://pop.argus-systems.ai/advisory/adv-040.htmlExploit, Patch, Third Party Advisory
- https://www.vulncheck.com/advisories/openbsd-mpls-do-error-kernel-stack-memory-disclosure-via-mpls-inputThird Party Advisory
- http://seclists.org/fulldisclosure/2026/Jun/17Exploit, Mailing List, Patch, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2026/06/19/3Exploit, Mailing List, Patch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.