6.9

CVE-2026-56099: openbsd Out-of-bounds Read

CVSS: 6.9v4.0MediumAnalyzed
Published 18-06-2026Last modified 14-07-2026
Open JSON

Vulnerability summary

CVE-2026-56099 is a medium (CVSS 6.9) Out-of-bounds Read vulnerability in openbsd. EPSS estimates a 0.50% chance of exploitation in the next 30 days, higher than 41.5% of scored vulnerabilities. 3 public exploits are recorded.

Overall risk
38/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.9/10
010
Medium · v4.0 (CVE.org)
EPSS score
0.50%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits3reference

Timeline

  1. 18-06-2026
    PublishedVulnerability first disclosed.
  2. 14-07-2026
    Last modifiedVulnerability information updated.

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 metrics

4 scores · 2 sources · 2 versions

EPSS trend

Probability

0.50%

Chance of exploitation in the next 30 days

Percentile

42%

Versus all other CVEs

30-day change

0.00 pp

From 0.50% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.50%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

3 found
  • referenceUnverified

    Exploit Reference (pop.argus-systems.ai)

    Maturity: unknown

  • referenceUnverified

    Exploit Reference (openwall.com)

    Maturity: unknown

  • referenceUnverified

    Exploit Reference (seclists.org)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Openbsd2 products
  • openbsd< 2026-06-18
  • src< 6a23123ec05f1eb29cfcaae0f3a468b2e1983cfd

1 vendor · 2 products

References

5 links