CVE-2026-59891 Credential confusion in @sigstore/oci can leak registry credentials to an attacker-controlled registry
An attacker can leak registry credentials by exploiting substring matching in credential selection, allowing access to sensitive authentication data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-59891?
CVE-2026-59891 is a critical vulnerability in sigstore-js, published on 14 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
sigstore-js provides JavaScript libraries for interacting with Sigstore services. Prior to 0.7.1, getRegistryCredentials() reads credentials from the Docker config file and selects an entry by checking whether any configured auth key contains the target registry string. Because this is a substring match rather than an exact host match, credentials configured for one registry can be selected for and transmitted to a different registry whose hostname has a substring relationship with a configured auth key. This issue is fixed in version 0.7.1.
Weakness: CWE-522
Which versions are affected by CVE-2026-59891?
2 open source packages ship an affected version, including @sigstore/oci.
| Package | Affected | Fixed in |
|---|---|---|
@sigstore/oci npm | All versions | 0.7.1 |
@sigstore/oci npm | All versions | 0.7.1 |
How do I fix CVE-2026-59891?
Upgrade @sigstore/oci to 0.7.1 or later.
Is CVE-2026-59891 being exploited?
There is no known exploitation of CVE-2026-59891 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-pf56-329r-95rw.