# CVE-2026-85491: Catalyst::Seal versions before 0.03 for Perl allow one request to disable a path or route a later one past an authorization check via a disp

> Attackers can bypass authorization checks or disable routes by exploiting a flawed dispatch memoization cache in Catalyst::Seal.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Sep 2026
- **Updated:** 25 Sep 2026
- **Also known as:** GHSA-5qhg-xgvp-wq2g

## What is CVE-2026-85491?

CVE-2026-85491 is a high-severity missing authorization vulnerability, published on 24 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Catalyst::Seal versions before 0.03 for Perl allow one request to disable a path or route a later one past an authorization check via a dispatch memo keyed on the request path alone.

Catalyst::Seal replaces the dispatcher's prepare_action with a version that memoises how a path resolved: which dispatch type matched, at which level, and what was left over as arguments. The key is the request path and nothing else. Action roles that match on the method, content type, scheme or query make that resolution depend on state the key does not carry, so the memo answers for a request it was not built from.

A path that resolves to no action is memoised as well, and replaying that entry returns without consulting any dispatch type, so no action is set and the request fails. A GET of a path whose action is declared POST-only therefore disables that path for every later request, the correct POST included. An entry that did resolve replays the level the earlier descent reached. Where a POST-only action sits below a shallower action on the same path, a GET memoises the shallow route, and a later POST is dispatched there with an auto() guarding the deeper controller never running.

The memo is cleared only when an action is registered, which happens at setup, so an entry lasts for the life of the process, and its cap of 2048 entries bounds how many paths one caller can disable. In the configuration measured, the misroute lands on the less privileged action, so it is an authorization check not running rather than a privilege gain.

Weakness: CWE-706 (Use of Incorrectly-Resolved Name or Reference), CWE-1023 (Incomplete Comparison with Missing Factors)

## Which versions are affected by CVE-2026-85491?


## How do I fix CVE-2026-85491?

No fix has been published for CVE-2026-85491 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-85491 being exploited?

There is no known exploitation of CVE-2026-85491 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-85491 and fix it if it is affected.

What it is: CVE-2026-85491 is a high-severity missing authorization vulnerability, published on 24 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-85491 in the wild and no public exploit code.

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-2026-85491/ (Markdown: https://insights.sbomify.com/CVE-2026-85491/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-85491
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-85491
- OSV: https://osv.dev/vulnerability/CVE-2026-85491

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-85491/
Summaries are generated and may contain mistakes; the official description above is the record.