Improper Certificate ValidationWeakness · CWE-295

CVE-2026-44309

MEDIUM · 5.3 CVSS v3.1 Published 2026-05-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
60/100
Remediation priority · Elevated
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Gitsign is a keyless Sigstore to signing tool for Git commits with your a GitHub / OIDC identity. Prior to 0.16.0, gitsign verify and gitsign verify-tag re-encode commit/tag objects through go-git's EncodeWithoutSignature before checking the signature, instead of verifying against the raw git object bytes. For malformed objects with duplicate tree headers, git-core and go-git parse different trees: git-core uses the first, go-git uses the second. A signature crafted over the go-git-normalized form (second tree) passes gitsign verify while git-core resolves the commit to a completely different tree. This breaks the invariant that a verified signature, the commit semantics git-core presents to users, and the object hash logged in Rekor all refer to the same content. This vulnerability is fixed in 0.16.0.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In gitsign versions prior to 0.16.0, the verify and verify-tag commands re-encode commit/tag objects through go-git's EncodeWithoutSignature before signature verification instead of using raw git object bytes. For malformed objects containing duplicate tree headers, go-git and git-core parse different trees (go-git uses the second, git-core uses the first), allowing a signature crafted over the go-git-normalized form to pass verification while git-core resolves the commit to a completely different tree.

MitigationUpgrade gitsign to version 0.16.0 or later. Audit recent commit history for any commits signed with older gitsign versions that may have exploited this vulnerability.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
High
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed gitsign version
    Run `gitsign version` or `gitsign --version` to retrieve the version number
    Affected if Version is prior to 0.16.0 (e.g., 0.15.0, 0.14.0, etc.)
  2. Check if gitsign is used in CI/CD or verification pipelines
    Search codebase or CI configuration files (e.g., .github/workflows/*.yml, .gitlab-ci.yml, Jenkinsfile) for usage of `gitsign verify` or `gitsign verify-tag` commands
    Affected if The verify or verify-tag commands are executed with a gitsign version prior to 0.16.0
  3. Inspect git configuration for gitsign signer
    Run `git config --get gitsign.enabled` or check if gitsign is configured as a gpg.signer or commit.gpgsign helper in `.gitconfig`
    Affected if Gitsign is enabled for commit signing and the installed version is prior to 0.16.0 (the vulnerability affects verification, not signing, but indicates active gitsign use)

You are affected if gitsign version 0.16.0 or later is not installed and the verify or verify-tag commands are used in your environment.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade gitsign to version 0.16.0 or later. Audit recent commit history for any commits signed with older gitsign versions that may have exploited this vulnerability.

Recommended fix High confidence

0.16.0

  1. Upgrade gitsign to version 0.16.0 or later to resolve the improper certificate validation vulnerability

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-44309 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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