UBUNTU-CVE-2026-39395

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Source

https://ubuntu.com/security/CVE-2026-39395

Import Source

https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-39395.json

JSON Data

https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-39395

Upstream

CVE-2026-39395

Published

2026-04-07T20:16:00Z

Modified

2026-05-20T16:25:38.156438709Z

Severity

4.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N CVSS Calculator
5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N CVSS Calculator
Ubuntu - medium

Summary

[none]

Details

Cosign provides code signing and transparency for containers and binaries. Prior to 3.0.6 and 2.6.3, cosign verify-blob-attestation may erroneously report a "Verified OK" result for attestations with malformed payloads or mismatched predicate types. For old-format bundles and detached signatures, this was due to a logic flaw in the error handling of the predicate type validation. For new-format bundles, the predicate type validation was bypassed completely. This vulnerability is fixed in 3.0.6 and 2.6.3.

References

Affected packages

Ubuntu:25.10 / cosign

Package

Name: cosign
Purl: pkg:deb/ubuntu/cosign?arch=source&distro=questing

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

2.*

2.4.3-1

2.5.0-2

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "2.5.0-2",
            "binary_name": "cosign"
        },
        {
            "binary_version": "2.5.0-2",
            "binary_name": "golang-github-sigstore-cosign-dev"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-39395.json"

Ubuntu:26.04:LTS / cosign