6.9
MEDIUM CVSS 4.0
CVE-2026-56099
OpenBSD mpls_do_error Kernel Stack Memory Disclosure via MPLS Input
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.

INFO

Published Date :

June 18, 2026, 7:29 p.m.

Last Modified :

June 18, 2026, 7:29 p.m.

Remotely Exploit :

Yes !

Source :

VulnCheck
Affected Products

The following products are affected by CVE-2026-56099 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
Solution
Update OpenBSD to fix an out-of-bounds read vulnerability in MPLS error handling.
  • Update OpenBSD to the latest version.
  • Apply the security patch for netmpls.
  • Review MPLS input processing.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-56099 vulnerability anywhere in the article.

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.