Bug#1142718: libdancer2-perl: CVE-2026-13577

[Salvatore Bonaccorso]

Source: libdancer2-perl
Version: 2.1.0-1
Severity: important
Tags: security upstream
X-Debbugs-Cc: carnil at debian.org, Debian Security Team <team at security.debian.org>
Control: found -1 1.1.2+dfsg-1

Hi,

The following vulnerability was published for libdancer2-perl.

CVE-2026-13577[0]:
| Dancer2 versions through 2.1.0 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.


If you fix the vulnerability please also make sure to include the
CVE (Common Vulnerabilities & Exposures) id in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2026-13577
    https://www.cve.org/CVERecord?id=CVE-2026-13577
[1] https://lists.security.metacpan.org/cve-announce/msg/41975698/

Regards,
Salvatore