{"id":"DEBIAN-CVE-2026-13577","details":"Dancer2 versions before 2.2.0 for Perl generate insecure session ids when required CSPRNG modules are unavailable.  Dancer2::Core::Role::SessionFactory::generate_id silently falls back to a built-in rand-derived session id unless both Math::Random::ISAAC::XS and Crypt::URandom are available.  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.","modified":"2026-09-21T08:47:38.661030473Z","published":"2026-07-20T08:16:28.987Z","upstream":["CVE-2026-13577"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-13577"}],"affected":[{"package":{"name":"libdancer2-perl","ecosystem":"Debian:12","purl":"pkg:deb/debian/libdancer2-perl?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.400001+dfsg-1","1.0.0+dfsg-1","1.1.0+dfsg-1","1.1.1+dfsg-1","1.1.2+dfsg-1","2.0.1-1","2.1.0-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-13577.json"}},{"package":{"name":"libdancer2-perl","ecosystem":"Debian:13","purl":"pkg:deb/debian/libdancer2-perl?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.1.2+dfsg-1","2.0.1-1","2.1.0-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-13577.json"}},{"package":{"name":"libdancer2-perl","ecosystem":"Debian:14","purl":"pkg:deb/debian/libdancer2-perl?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.1.2+dfsg-1","2.0.1-1","2.1.0-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-13577.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H"}]}