regclient may leak authentication credentials to external blob stores

Exploitation

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

CVSS

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

EPSS

• CVE-2026-49349: 0.31% estimated exploitation activity in the next 30 days; percentile 23.51 (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.

Credentials for a registry may be inadvertently leaked to external servers. A prerequisite for this attack is a malicious registry server, a malicious blob store, or a registry that does not restrict the external URLs for foreign blobs. Example attack A malicious registry serves an OCI image manifest containing a layer descriptor with a urls field pointing to an attacker controlled host: When regclient fetches the image and the primary blob request to the registry fails, it falls back to the URLs in the layer descriptor. If the external server requests authentication, regclient would send the credentials for the original registry server. Timeline - 2026-05-25: Advisory submitted - 2026-05-26: Fix released Credit Theodoros Lampropoulos, Threat Detection Engineer, Odyssey Cyber Security

Published by the source

26 Jun 2026, 22:43 UTC

Last modified by the source

26 Jun 2026, 22:43 UTC

Source last checked

26 Oct 2026, 15:24 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-qvqc-4c52-x6qp

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-49349

Advisory: regclient may leak authentication credentials to external blob stores
IDs: CVE-2026-49349, GHSA-qvqc-4c52-x6qp
Record: https://patchnext.com/advisories/cve-2026-49349 (revision 1, source checked 26 Oct 2026, 15:24 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/regclient/regclient 0.11.5. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/regclient/regclient: affected <= 0.11.4; fixed in 0.11.5

## Suggested inspection (read-only)
- Go github.com/regclient/regclient: 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/regclient/regclient.
- 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-qvqc-4c52-x6qp (GitHub-reviewed advisory GHSA-qvqc-4c52-x6qp lists affected ranges: Go github.com/regclient/regclient >=0 <=0.11.4)

Commands are suggestions: review each one before running it.