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Fencer Vulns
high 7.4

CVE-2026-75939 json

Openshift/oc-mirror: release signature verification: openpgp signatureerror checked before signed body is consumed

published 2026-09-21 49 d ago modified 2026-11-06 2 d ago also EUVD-2026-83918

cvss
7.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 31%
public exploits
0
none known

Summary

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.

Patch / fix

  • Red Hat Red Hat OpenShift Container Platform 4.18 1790828598

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-75939 updated cvss 7.4

openshift/oc-mirror: Release signature verification: OpenPGP SignatureError checked before signed body is consumed

  • Red Hat OpenShift Container Platform 5 openshift4/oc-mirror-plugin-rhel9, openshift5/oc-mirror-plugin-rhel9
    affected: workaround, no fix available
  • Red Hat OpenShift Container Platform 4.18 openshift4/oc-mirror-plugin-rhel9 1790828598
    fixed: vendor fix RHSA-2026:79039
  • Red Hat OpenShift Container Platform 4 openshift4/oc-mirror-plugin-rhel8
    not affected: component not present
  • Red Hat OpenShift Container Platform 4.18 openshift4/frr-rhel9 1790826545, openshift4/ose-cli-rhel9 1790882345, openshift4/ose-pod-rhel9 1790853956, openshift4/ose-etcd-rhel9 1791320060, openshift4/ose-tests-rhel9 1791373456, openshift4/ose-tools-rhel9 1791372072, +180 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
46 d ago

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 31% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected products

  • Red Hat Red Hat OpenShift Container Platform 4.18
  • Red Hat Red Hat OpenShift Container Platform 4
  • Red Hat Red Hat OpenShift Container Platform 5

Classification

Weakness
  • CWE-347 Improper Verification of Cryptographic Signature

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.