Cosign vulnerable to possible endless data attack from attacker-controlled registry

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2023-46737: 0.64% estimated exploitation activity in the next 30 days; percentile 50.71 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Cosign is susceptible to a denial of service by an attacker controlled registry. An attacker who controls a remote registry can return a high number of attestations and/or signatures to Cosign and cause Cosign to enter a long loop resulting in an endless data attack. The root cause is that Cosign loops through all attestations fetched from the remote registry in pkg/cosign.FetchAttestations. The attacker needs to compromise the registry or make a request to a registry they control. When doing so, the attacker must return a high number of attestations in the response to Cosign. The result will be that the attacker can cause Cosign to go into a long or infinite loop that will prevent other users from verifying their data. In Kyvernos case, an attacker whose privileges are limited to making requests to the cluster can make a request with an image reference to their own registry, trigger the infinite loop and deny other users from completing their admission requests.…

Published by the source

8 Nov 2023, 15:02 UTC

Last modified by the source

11 Dec 2023, 20:55 UTC

Source last checked

26 Oct 2026, 15:00 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-vfp6-jrw2-99g9

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# Patch Next advisory brief: CVE-2023-46737

Advisory: Cosign vulnerable to possible endless data attack from attacker-controlled registry
IDs: CVE-2023-46737, GHSA-vfp6-jrw2-99g9
Record: https://patchnext.com/advisories/cve-2023-46737 (revision 1, source checked 26 Oct 2026, 15:00 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 3.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/sigstore/cosign 1.13.2; github.com/sigstore/cosign/v2 2.2.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/sigstore/cosign: affected <= 1.13.1; fixed in 1.13.2
- Go github.com/sigstore/cosign/v2: affected < 2.2.1; fixed in 2.2.1

## Suggested inspection (read-only)
- Go github.com/sigstore/cosign: check the installed version with your package manager.
- Go github.com/sigstore/cosign/v2: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/sigstore/cosign, github.com/sigstore/cosign/v2.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-vfp6-jrw2-99g9 (GitHub-reviewed advisory GHSA-vfp6-jrw2-99g9 lists affected ranges: Go github.com/sigstore/cosign/v2 >=0 =0 <=1.13.1)

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