CVE-2026-39395 (GCVE-0-2026-39395)
Vulnerability from cvelistv5 – Published: 2026-04-07 20:06 – Updated: 2026-04-08 15:49
VLAI
EPSS
VEX
Title
Cosign's verify-blob-attestation reports false positive when payload parsing fails
Summary
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.
Severity
4.3 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-754 - Improper Check for Unusual or Exceptional Conditions
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://github.com/sigstore/cosign/security/advis… | x_refsource_CONFIRM |
Impacted products
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
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