CVE-2026-13577
- Source
- https://cve.org/CVERecord?id=CVE-2026-13577
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-13577.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-13577
- Downstream
- Published
- 2026-07-20T07:11:10.403Z
- Modified
- 2026-07-21T03:46:10.556231482Z
- Severity
-
- 8.2 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H CVSS Calculator
- Summary
- Dancer2 versions through 2.1.0 for Perl generate insecure session ids when CSPRNG modules are unavailable
- Details
-
Dancer2 versions through 2.1.0 for Perl generate insecure session ids when CSPRNG modules are unavailable.
Dancer2::Core::Role::SessionFactory::generate_id silently falls back to a built-in rand-derived session id when both Math::Random::ISAAC::XS and Crypt::URandom are unavailable.
The fallback session id is generated from a SHA-1 hash of a call to the built-in rand function, the absolute path of the Dancer2::Core::Role::SessionFactory module, an internal counter, the process id, the module instance memory address, and a shuffled string of characters (using the List::Util::shuffle function, which also uses the built-in rand function).
These are all low-entropy and easily guessed sources.
The built-in rand() function is seeded with 32-bits and considered unsuitable for security applications.
Predictable session ids could allow an attacker to gain access to systems.
- Database specific
{ "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/13xxx/CVE-2026-13577.json", "cna_assigner": "CPANSec", "cwe_ids": [ "CWE-338", "CWE-340" ] }- References
-
- https://cpan.org/modules
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/13xxx/CVE-2026-13577.json
- https://github.com/PerlDancer/Dancer2
- https://github.com/PerlDancer/Dancer2/blob/v2.1.0/lib/Dancer2/Core/Role/SessionFactory.pm#L142
- https://nvd.nist.gov/vuln/detail/CVE-2026-13577
- https://www.cve.org/CVERecord?id=CVE-2026-5080