Vulnerability in Red Hat Openshift Container Platform 4
CVE-2026-75939
A flaw was found in openshift/oc-mirror. The tool incorrectly verifies PGP (Pretty Good Privacy) release image signatures by checking for signature errors before the entire signed body is processed, leading to a bypass of the signature verification. A remote attacker, by intercepting or manipulating network traffic to the signature endpoint, could exploit this to craft a PGP message with a valid Red Hat release key ID but a forged signature. This enables the `oc-mirror` tool to accept and mirror a malicious release payload into a disconnected registry, potentially compromising the integrity of software deployments.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (31.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 31.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
Weakness classification (CWE)
References
- access.redhat.com/security/cve/CVE-2026-75939 (vdb-entry)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking)
- access.redhat.com/errata/RHSA-2026:79039 (vendor-advisory)
Frequently asked questions
- What is CVE-2026-75939?
- CVE-2026-75939 is a high-severity vulnerability in Red Hat Openshift Container Platform 4, classified under Improper Verification of Cryptographic Signature. CVSS score: 7.4/10. Published 2026-09-21.
- How severe is CVE-2026-75939?
- High severity. CVSS v3 base score is 7.4 out of 10.