# CVE-2026-118763: sigstore-js credential leak in OCI registry blob upload

Source: https://junglewise.ai/threats/cve-2026-118763-sigstore-js-provides-javascript-libraries-for-interacting-with  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-29. Updated: 2026-10-29  
License: CC BY 4.0 with a link back

CVE-2026-118763 · Severity: high · CVSS 7.4 · Published 2026-10-29

sigstore-js is a library used to sign and verify software artifacts using Sigstore, a service that helps developers prove the authenticity of code releases. A malicious or compromised container registry can trick the library into sending authentication credentials (bearer tokens or usernames and passwords) to an attacker-controlled server when uploading artifacts. This could allow attackers to gain unauthorized access to other registries the user authenticates to.

Technologies: [Sigstore-Js](https://junglewise.ai/threats/technologies/sigstore-js). Vendors: [npm](https://junglewise.ai/threats/vendors/npm), [Sigstore](https://junglewise.ai/threats/vendors/sigstore).

## Quick answers

**Is CVE-2026-118763 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-118763 being exploited in the wild.

**How severe is CVE-2026-118763?** High severity, with a CVSS score of 7.4, published 29 October 2026.

**Which products and versions are affected?** @sigstore/oci (npm) <= 0.7.1, SEMVER:introduced=0,fixed=0.7.2; Sigstore-Js before 0.7.2.

**Is there a fix for CVE-2026-118763?** Yes. @sigstore/oci (npm): upgrade to 0.7.2 or later. Until then: Restrict interactions with untrusted or unverified OCI registries, or use the `fetchOpts.allowedPrivateOrigins` option to explicitly allowlist safe registry destinations. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-118763 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-118763?** Check whether you run @sigstore/oci (npm) or Sigstore-Js at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- @sigstore/oci (npm): upgrade to 0.7.2 or later

  ```sh
  npm install @sigstore/oci@0.7.2
  ```


Restrict interactions with untrusted or unverified OCI registries, or use the `fetchOpts.allowedPrivateOrigins` option to explicitly allowlist safe registry destinations.

## Technical details

The RegistryClient.uploadBlob() method sends a PUT request to an absolute blob-upload Location header supplied by the registry without validating that the destination's origin or scheme matches the trusted registry. Registry credentials stored as HTTP client defaults are sent to any destination. An attacker-controlled registry can redirect users to a malicious host and receive their authentication headers. The fix separates registry credentials from client-wide defaults and restricts their transmission to the legitimate registry origin only.

## Affected products

- sigstore sigstore-js before 0.7.2

## Identifiers

- CVE-2026-118763
- GHSA-j63v-mwhm-56jx

## Timeline

- 2026-10-29: advisory: CVE-2026-118763 published

## References

- [https://github.com/sigstore/sigstore-js/commit/b855f46cfe81f26481c6d3f4b333dfd00f2fd1b1](https://github.com/sigstore/sigstore-js/commit/b855f46cfe81f26481c6d3f4b333dfd00f2fd1b1)
- [https://github.com/sigstore/sigstore-js/commit/e4ca65c3ab3c675456ab9b0bd04217ceccad3558](https://github.com/sigstore/sigstore-js/commit/e4ca65c3ab3c675456ab9b0bd04217ceccad3558)

## Related threats

- [sigstore-js insufficient verification of data authenticity in @sigstore/verify](https://junglewise.ai/threats/cve-2026-48816-sigstore-js-insufficient-verification-of-data-authenticity-in)
- [sigstore-js improper verification of certificate OIDs](https://junglewise.ai/threats/cve-2026-48815-sigstore-js-improper-verification-of-certificate-oids)
- [sigstore-js signature type-binding failure in @sigstore/core](https://junglewise.ai/threats/cve-2026-48758-sigstore-js-signature-type-binding-failure-in-sigstore-core)
- [Sigstore sigstore-js credential leakage via registry substring match](https://junglewise.ai/threats/cve-2026-59891-sigstore-sigstore-js-credential-leakage-via-registry-substring)