What is 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 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.
The record classifies CVE-2026-85491 under weakness classes CWE-1023, CWE-706. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. The identifier was first published 11 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 8.8 — HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS (FIRST)
- 0.3% probability of exploitation in the next 30 days, higher than 26.9% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 5.5/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-09-24, last modified 2026-09-25
Is CVE-2026-85491 being exploited?
It currently carries a trending score of 35 in the Threadlinqs vulnerability feed.
Affected products and versions
No affected-product or package list has been recorded for CVE-2026-85491 in the tracked sources. The vendor advisory and the references below are the authoritative statement of what is affected.
How to fix CVE-2026-85491
No vendor patch reference has been recorded for CVE-2026-85491 in the tracked sources. Follow the references below for a fix, and treat any affected deployment as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-85491
No threat campaign in the Threadlinqs corpus currently references CVE-2026-85491, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.
Sources
Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.