# CVE-2026-118763: @sigstore/oci sends the registry Authorization header to a cross-host blob-upload Location


- **Severity:** High 7.4 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 29 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-j63v-mwhm-56jx

## What is CVE-2026-118763?

CVE-2026-118763 is a high-severity vulnerability in sigstore-js, published on 29 Oct 2026. 

### Official description

sigstore-js provides JavaScript libraries for interacting with Sigstore services. Prior to 0.7.2, packages/oci/src/registry.ts contains a RegistryClient.signIn() method that stores registry Authorization and Docker configuration headers as defaults on a shared HTTP client, while RegistryClient.uploadBlob() sends a fresh PUT to an absolute blob-upload Location supplied by the registry without checking that its origin or scheme matches the registry. A malicious or compromised registry can therefore direct a user pushing an artifact through attachArtifactToImage() to an attacker-controlled host and receive the registry bearer token, Basic credentials, or custom authentication headers. Redirect-time header stripping does not prevent the leak because the cross-host PUT is a new explicit request rather than a followed redirect. This is a residual of CVE-2026-59891, whose fix changed credential selection in credentials.ts but did not constrain where credentials are sent from registry.ts. Version 0.7.2 fixes the issue by separating registry credentials from client-wide defaults and sending them only to the registry origin.

Weakness: CWE-522 (Insufficiently Protected Credentials)

## Which versions are affected by CVE-2026-118763?


## How do I fix CVE-2026-118763?

No fix has been published for CVE-2026-118763 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-118763 being exploited?

There is no known exploitation of CVE-2026-118763 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-118763 and fix it if it is affected.

What it is: CVE-2026-118763 is a high-severity vulnerability in sigstore-js, published on 29 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-118763 in the wild and no public exploit code.

Affected product: sigstore-js. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-118763/ (Markdown: https://insights.sbomify.com/CVE-2026-118763/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-118763
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-118763
- OSV: https://osv.dev/vulnerability/CVE-2026-118763

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-118763/
Summaries are generated and may contain mistakes; the official description above is the record.