CVE-2026-56099

Name: CVE-2026-56099
Creator: NVD / NIST
Published: 2026-06-18T20:16:15.37+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.9/10EPSS 0.36%

Last modified Jun 23, 2026

CVE-2026-56099 is a medium-severity vulnerability rated 6.9/10 on the CVSS scale. 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.. EPSS estimates a 0.36% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CVSS 4.0

6.9/10

CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.36%

27.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-125

References

Timeline

Published: Jun 18, 2026
Last Modified: Jun 23, 2026
Status: Undergoing Analysis

Frequently Asked Questions

What is CVE-2026-56099?

How severe is CVE-2026-56099?

CVE-2026-56099 has a CVSS score of 6.9/10 (MEDIUM severity). The EPSS model estimates a 0.36% probability of exploitation in the next 30 days.

How do I fix CVE-2026-56099?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-56099?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST