juju/utils leaks private key in certs

Exploitation

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

CVSS

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

EPSS

• CVE-2025-6224: 0.16% estimated exploitation activity in the next 30 days; percentile 4.95 (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 Certs generated by v4 contain their private key. Details Background Recently, I encountered an API in Go that’s easy to misuse: sha512.Sum384 and sha512.New384().Sum look very similar and behave very differently. https://go.dev/play/p/kDCqqoYk84k demonstrates this. I want to discuss extending static analysis to detect this case with the go community, but before I do that, I want to make a best-effort pass at open-source projects to fix the existing bugs. I figured that if there were any vulnerabilities out there, they would be easy to find once that discussion begins, so it’s better to address them early. This work is a hobby project and has no affiliation with my employer, so I may be slow to respond due to existing commitments. PoC https://go.dev/play/p/vSW0U3Hq4qk Impact This code (cert.NewLeaf) generates certs with the SubjectKeyId set to sha512.New384().Sum(/ private / key). If a cert which was generated by cert.NewLeaf is transferred over the network in plaintext, as is…

Published by the source

1 Jul 2025, 17:35 UTC

Last modified by the source

1 Jul 2025, 17:35 UTC

Source last checked

26 Oct 2026, 15:09 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-h34r-jxqm-qgpr

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# Patch Next advisory brief: CVE-2025-6224

Advisory: juju/utils leaks private key in certs
IDs: CVE-2025-6224, GHSA-h34r-jxqm-qgpr
Record: https://patchnext.com/advisories/cve-2025-6224 (revision 1, source checked 26 Oct 2026, 15:09 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/juju/utils/v4/cert 4.0.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/juju/utils/v4/cert: affected <= 4.0.3; fixed in 4.0.4

## Suggested inspection (read-only)
- Go github.com/juju/utils/v4/cert: 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/juju/utils/v4/cert.
- 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-h34r-jxqm-qgpr (GitHub-reviewed advisory GHSA-h34r-jxqm-qgpr lists affected ranges: Go github.com/juju/utils/v4/cert >=0 <=4.0.3)

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