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Notation GoApplication · Notaryproject

CVE-2023-25656

HIGH · 7.5 CVSS v3.1 Published 2023-02-20
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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
notation-go is a collection of libraries for supporting Notation sign, verify, push, and pull of oci artifacts. Prior to version 1.0.0-rc.3, notation-go users will find their application using excessive memory when verifying signatures. The application will be killed, and thus availability is impacted. The problem has been patched in the release v1.0.0-rc.3. Some workarounds are available. Users can review their own trust policy file and check if the identity string contains `=#`. Meanwhile, users should only put trusted certificates in their trust stores referenced by their own trust policy files, and make sure the `authenticity` validation is set to `enforce`.

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

notation-go versions prior to 1.0.0-rc.3 contain a memory exhaustion vulnerability during signature verification. When the trust policy file's identity string contains the characters `=#`, the verification process consumes excessive memory, causing the application to be killed and impacting availability.

MitigationReview trust policy files for identity strings containing `=#`, ensure only trusted certificates are in trust stores, set authenticity validation to `enforce`, and upgrade to version 1.0.0-rc.3 or later.

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

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Notation GoApplication
Affected:= 0.7.0= 0.8.0= 0.9.0

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
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

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 if notation-go is installed
    Run `notation version` or check for the notation binary in your PATH (e.g., `which notation` on Linux/macOS or `where notation` on Windows)
    Affected if notation command is found and executable
  2. Determine the installed notation-go version
    Run `notation version` and note the version number in the output
    Affected if The version is 0.7.0, 0.8.0, or 0.9.0 (or any version prior to 1.0.0-rc.3)
  3. Locate trust policy files
    Check the default notation trust policy location: `~/.notation/trustpolicy.json` or the path specified by the NOTATION_TRUST_POLICY environment variable. Custom paths may also be set via `--trust-policy` flag during verification.
    Affected if A trust policy file exists and is configured for signature verification
  4. Inspect identity strings in trust policy for the trigger characters
    Open the trust policy JSON file and examine each identity string in the `trustPolicy.identity` or `trustPolicy.identities` fields. Search for the exact character sequence `=#` within these string values.
    Affected if Any identity string value contains the characters `=#` (for example: `identity = "example=#test"` or similar)
  5. Verify trust policy is actively used for signature verification
    Confirm that signature verification is performed using this trust policy (e.g., by running `notation verify` with the relevant policy or checking if it is set as default)
    Affected if The policy with the `=#` identity string is used for verification operations

You are affected if notation-go version 0.7.0, 0.8.0, or 0.9.0 is installed AND a configured trust policy file contains an identity string with the characters `=#`.

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

Review trust policy files for identity strings containing `=#`, ensure only trusted certificates are in trust stores, set authenticity validation to `enforce`, and upgrade to version 1.0.0-rc.3 or later.

Recommended fix High confidence

v1.0.0-rc.3 or later (notation-go)

  1. 1. Identify the notation-go dependency in your project (e.g., check go.mod for 'notation-go' or 'github.com/notaryproject/notation-go')
  2. 2. Update the notation-go dependency to version 1.0.0-rc.3 or later using: go get github.com/notaryproject/[email protected]
  3. 3. Run go mod tidy to update all related dependencies
  4. 4. Rebuild and test your application to ensure signature verification still works correctly
  5. 5. Verify the memory usage issue is resolved by testing signature verification workloads

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

Fix this in Notation Go Scoped from the published advisory
  • Consultation4.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,330
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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-2023-25656 in production — separate from our analysis above.

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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
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data