CVE-2025-40920
CVE-2025-40920 is a high-severity vulnerability with a CVSS 3.x base score of 8.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-338.
Key facts
- Severity: High (CVSS 3.x base score 8.6)
- EPSS exploit prediction: 0% (31st percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2025-24168
- Weakness: CWE-338
- Published:
- Last modified:
Description
Catalyst::Authentication::Credential::HTTP versions 1.018 and earlier for Perl generate nonces using the Perl Data::UUID library. * Data::UUID does not use a strong cryptographic source for generating UUIDs. * Data::UUID returns v3 UUIDs, which are generated from known information and are unsuitable for security, as per RFC 9562. * The nonces should be generated from a strong cryptographic source, as per RFC 7616.
Frequently asked questions
- What is CVE-2025-40920?
- Catalyst::Authentication::Credential::HTTP versions 1.018 and earlier for Perl generate nonces using the Perl Data::UUID library. * Data::UUID does not use a strong cryptographic source for generating UUIDs. * Data::UUID returns v3 UUIDs, which are generated from known information and are unsuitable for security, as per RFC 9562. * The nonces should be generated from a strong cryptographic source, as per RFC 7616.
- How severe is CVE-2025-40920?
- CVE-2025-40920 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability low.
- Is CVE-2025-40920 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2025-40920?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2025-40920 have an EU (EUVD) identifier?
- Yes. CVE-2025-40920 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-24168.
- When was CVE-2025-40920 published?
- CVE-2025-40920 was published on 2025-08-11 and last updated on 2026-06-17.
References
- https://datatracker.ietf.org/doc/html/rfc7616#section-5.12
- https://datatracker.ietf.org/doc/html/rfc9562#name-security-considerations
- https://github.com/perl-catalyst/Catalyst-Authentication-Credential-HTTP/commit/ad2c03aad95406db4ce35dfb670664ebde004c18
- https://github.com/perl-catalyst/Catalyst-Authentication-Credential-HTTP/pull/1
- https://metacpan.org/release/ETHER/Catalyst-Authentication-Credential-HTTP-1.018/source/lib/Catalyst/Authentication/Credential/HTTP.pm#L391
- https://security.metacpan.org/patches/C/Catalyst-Authentication-Credential-HTTP/1.018/CVE-2025-40920-r1.patch
- http://www.openwall.com/lists/oss-security/2025/08/12/1
Other CWE-338 vulnerabilities
- CVE-2026-56141 — Critical (CVSS 9.8): In JetBrains Hub before 2026.1.13757, 2025.3.148033, 2025.2.148048, 2025.1.148120, 2024.3.148430, 2024.2.148429 account…
- CVE-2026-3256 — Critical (CVSS 9.8): HTTP::Session versions before 0.54 for Perl defaults to using insecurely generated session ids. HTTP::Session defaults…
- CVE-2025-15604 — Critical (CVSS 9.8): Amon2 versions before 6.17 for Perl use an insecure random_string implementation for security functions. In versions…
- CVE-2025-40926 — Critical (CVSS 9.8): Plack::Middleware::Session::Simple versions before 0.05 for Perl generates session ids insecurely. The default session…
- CVE-2026-2439 — Critical (CVSS 9.8): Concierge::Sessions versions from 0.8.1 before 0.8.5 for Perl generate insecure session ids. The generate_session_id…
- CVE-2025-15578 — Critical (CVSS 9.8): Maypole versions from 2.10 through 2.13 for Perl generates session ids insecurely. The session id is seeded with the…