# Name constraints were accepted for certificates asserting a wildcard name

Advisory record · `GHSA-xgp8-3hg3-c2mh`

- **Identifiers:** `GHSA-xgp8-3hg3-c2mh` · `CVE-2026-93601` · `RUSTSEC-2026-0099`
- **State:** Confirmed
- **Severity:** CVSS 2.1 Low
- **Critical:** No
- **Weakness (CWE):** [CWE-295](https://cwe.mitre.org/data/definitions/295.html)
- **Tags:** [Weak cryptography or TLS](https://agentprime.io/advisories/tag/weak-crypto.md)
- **Published:** 14 Apr 2026
- **Updated:** 19 Sept 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 14 Apr 2026, 12:00 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `rustls-webpki` (crates.io): affected `>=0.0.0-0, <0.103.12 || >=0.104.0-alpha.1, <0.104.0-alpha.6`; fixed in `0.103.12`, `0.104.0-alpha.6`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Versions of rustls-webpki before 0.103.12 and from 0.104.0-alpha.1 before 0.104.0-alpha.6 accept permitted DNS name constraints for certificates asserting a wildcard name, so a wildcard name can fall outside the constraint it should respect. Exploiting this requires a certificate that has already been misissued, since the check only applies after signature verification. Upgrade to rustls-webpki 0.103.12 or 0.104.0-alpha.6.

Written 8 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 2.1 Low, CVSS 4.0: `CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N`, from CNA (VulnCheck)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0020, the 10th percentile, on 12 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 15:17 UTC: First seen by agentprime
- 31 Oct 2026, 15:17 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/RUSTSEC-2026-0099)

## Sources

- [GitHub Advisory Database: GHSA-xgp8-3hg3-c2mh](https://github.com/advisories/GHSA-xgp8-3hg3-c2mh)
- [OSV: GHSA-xgp8-3hg3-c2mh](https://osv.dev/vulnerability/GHSA-xgp8-3hg3-c2mh)
- <https://crates.io/crates/rustls-webpki>
- <https://rustsec.org/advisories/RUSTSEC-2026-0099.html>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-xgp8-3hg3-c2mh>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-xgp8-3hg3-c2mh/>. Everything for agents: <https://agentprime.io/llms.txt>.