6.3

CVE-2026-39828: Invoking bypass of certificate restrictions in golang.org/x/crypto/ssh

Modified
AliasesUBUNTU-CVE-2026-39828DEBIAN-CVE-2026-39828CGA-229c-f8cf-m46v
Published 22-05-2026Last modified 18-09-2026

Vulnerability summary

CVE-2026-39828 is a medium (CVSS 6.3) Improper Certificate Validation vulnerability in golang crypto. EPSS estimates a 0.37% chance of exploitation in the next 30 days, higher than 30.8% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 6.3, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
6.3/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.37%
0%100%
Low · -0.17 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 56 · Related 57
OPENSUSE-SU-2026:10856-1OPENSUSE-SU-2026:10949-1OPENSUSE-SU-2026:10966-1OPENSUSE-SU-2026:11126-1OPENSUSE-SU-2026:11305-1OPENSUSE-SU-2026:11314-1

Timeline

  1. 22-05-2026
    PublishedVulnerability first disclosed.
  2. 18-09-2026
    Last modifiedVulnerability information updated.

Description

When an SSH server authentication callback returned PartialSuccessError with non-nil Permissions, those permissions were silently discarded, potentially dropping certificate restrictions such as force-command after a second factor succeeded. Returning non-nil Permissions with PartialSuccessError now results in a connection error.

CVSS metrics

7 scores · 7 sources · 1 version

EPSS trend

Probability

0.37%

Chance of exploitation in the next 30 days

Percentile

31%

Versus all other CVEs

30-day change

Decrease -0.17 pp

From 0.54% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Chainguard200 products
  • aactl< 0.4.12-r53
  • actAll versions (No fix recorded)
  • actions-runner-controllerAll versions (No fix recorded)
  • actions-runner-controller-fipsAll versions (No fix recorded)
  • ageAll versions (No fix recorded)

1 vendor · 200 products · Showing 200 of 2854

References

64 links
Show all 64 references