CVE-2026-9733Mojolicious::Plugin::Web::Auth::OAuth2 versions through 0.17 for Perl have an insecure default state parameter
- 9.1CriticalCVSS base score
- 0.52%Exploitation in 30 daysEPSS · top 55% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
Mojolicious::Plugin::Web::Auth::OAuth2 versions through 0.17 for Perl have an insecure default state parameter. When no state generator is specified in the constructor, the module defaults to using a SHA-1 hash of predictable and low-entropy sources, including the epoch time (which is leaked via the HTTP Date header) and a call to Perl's built-in rand function. A predictable state allows an attacker to hijack another user's session through cross site request forgery (CSRF).
Timeline
ID reserved
By CPANSec
- 27 days later
· 27 days later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | Critical9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| NVDNVD · Deferred | 3.1 | Critical9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.52% · top 55% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.1.
Affected products
HAYAJO · Mojolicious::Plugin::Web::Auth::OAuth2
- affected ≤ 0.17
What to do
Workaround: Users should specify a state_generator function in the plugin configuration that uses a secure CSPRNG such as Crypt::PRNG or (for Mojolicious 9.46 or later) the Mojo::Util::random_bytes function. For example, plugin 'Web::Auth', module => 'OAuth2', ... state_generator => sub { unpack("H*", Mojo::Util::random_bytes(20)) };
References
References4
- https://metacpan.org/release/HAYAJO/Mojolicious-Plugin-Web-Auth-0.17/source/lib/Mojolicious/Plugin/Web/Auth/OAuth2.pm#L129-131 (opens in a new tab)
- https://datatracker.ietf.org/doc/html/rfc6749#section-10.12 (opens in a new tab)technical-description
- https://security.metacpan.org/patches/M/Mojolicious-Plugin-Web-Auth/0.17/CVE-2026-9733-r2.patch (opens in a new tab)patch
- http://www.openwall.com/lists/oss-security/2026/06/23/1 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-38421 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-9733)Record last updated .