Security readout for executives and security teams
Plain-English summary
Cosign versions before 2.6.2 and 3.0.4 may accept a crafted verification bundle using a valid Rekor transparency-log entry that does not actually match the artifact, signature, or key. This can undermine auditability of signing events and supply-chain trust decisions, especially where Cosign verification gates releases or deployments.
Executive priority
Treat as a supply-chain integrity issue with moderate urgency. It does not indicate remote compromise by itself, but it can weaken verification controls that protect software releases. Upgrade promptly where Cosign is part of production deployment or compliance evidence.
Technical view
The issue is improper verification of authenticity (CWE-345). Under certain conditions, Cosign bundle verification failed to compare the artifact digest, signature, and public key against the embedded Rekor entry. A valid but unrelated Rekor entry could be accepted. The advisory states this is patched in Cosign 2.6.2 and 3.0.4.
Likely exposure
Organizations are exposed if they use Sigstore Cosign versions below 2.6.2 or below 3.0.4 for bundle-based verification of containers or binaries. Exposure is higher where Cosign results are used for deployment authorization, provenance checks, or release audit evidence.
Exploitation context
Sources describe a malicious actor who has already compromised a user identity or signing key constructing a valid-looking Cosign bundle with an arbitrary Rekor entry. The CVSS vector is local, low complexity, low privilege. No provided source or KEV status indicates active exploitation.
Researcher notes
The key security failure is accepting any valid Rekor response without binding it to the artifact digest, signature, and public key. Public sources identify patches and the fixing commit/PR, but do not provide evidence of exploitation in the wild.
Mitigation direction
- Upgrade Cosign to version 2.6.2, 3.0.4, or later.
- Prioritize systems where Cosign verification gates production deployments.
- Review vendor advisory and release notes for environment-specific guidance.
- Reassess trust decisions made using vulnerable Cosign bundle verification.
Validation and detection
- Inventory Cosign versions across developer workstations, CI, build, and deployment systems.
- Identify pipelines using Cosign bundle verification with Rekor transparency-log entries.
- Confirm upgraded systems run Cosign 2.6.2, 3.0.4, or later.
- Review recent signing audit records for unexpected or unauditable Rekor linkage.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-345: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-22703 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N1.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/sigstore/cosign/security/advisories/GHSA-whqx-f9j3-ch6mCVE reference · x_refsource_CONFIRM
- https://github.com/sigstore/cosign/pull/4623CVE reference · x_refsource_MISC
- https://github.com/sigstore/cosign/commit/6832fba4928c1ad69400235bbc41212de5006176CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Insufficient Verification of Data Authenticity
Insufficient Verification of Data Authenticity represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.