CVE-2026-22703Public exploit

Artifact verification bypass via unrelated Rekor entry

Published Jan 10, 2026 · Updated Jan 10, 2026

Improper verification in Sigstore Cosign v2 2.6.1 and earlier and Cosign v3 3.0.3 and earlier allows local users to validate crafted bundles. The Rekor bundle-verification path verifies the entry signature but fails to compare the artifact digest, artifact signature, and trusted public key with the entry contents. Exploitation requires a compromised signing identity or key and an affected trusted-root configuration; default Cosign v3 signing and verification flags are unaffected, while v2 defaults are affected.

CVSS severity5.5
Medium
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper verification in Sigstore Cosign v2 2.6.1 and earlier and Cosign v3 3.0.3 and earlier allows local users to validate crafted bundles. The Rekor bundle-verification path verifies the entry signature but fails to compare the artifact digest, artifact signature, and trusted public key with the entry contents. Exploitation requires a compromised signing identity or key and an affected trusted-root configuration; default Cosign v3 signing and verification flags are unaffected, while v2 defaults are affected.

The record

CVE
CVE-2026-22703
Published
Jan 10, 2026
Updated
Jan 10, 2026
Vendor
Sigstore
Product
Cosign
Classifications
CWE-345, T1553.002
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.6.2
  2. Affected versionversion=< 3.0.4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Sigstore · Cosignversion=< 2.6.2; version=< 3.0.4

Published CVSS scores

5.5GitHubCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-345Insufficient Verification of Data Authenticity
T1553.002Subvert Trust Controls: Code Signing

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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