CPANSA-Dancer-2026-5080: Dancer vulnerability
| Publisher | giterlizzi | Document category | csaf_security_advisory |
|---|---|---|---|
| Initial release date | 2026-04-30T00:00:00 | Engine | CSAF Perl Toolkit 0.26 |
| Current release date | 2026-04-30T00:00:00 | Build Date | |
| Current version | 1 | Status | final |
| CVSS v3.1 Base Score | 5.9 | Severity | |
| Original language | Language | en | |
| Also referred to | |||
Vulnerability Description
Dancer::Session::Abstract versions through 1.3522 for Perl generates session ids insecurely. The session id is generated from summing the character codepoints of the absolute pathname with the process id, the epoch time and calls to the built-in rand() function to return a number between 0 and 999-billion, and concatenating that result three times. The path name might be known or guessed by an attacker, especially for applications known to be written using Dancer with standard installation locations. The epoch time can be guessed by an attacker, and may be leaked in the HTTP header. The process id comes from a small set of numbers, and workers may have sequential process ids. The built-in rand() function is seeded with 32-bits and is considered unsuitable for security applications. Predictable session ids could allow an attacker to gain access to systems.
Vulnerabilities
CVE-2026-5080
Vulnerability DescriptionDancer::Session::Abstract versions through 1.3522 for Perl generates session ids insecurely.
The session id is generated from summing the character codepoints of the absolute pathname with the process id, the epoch time and calls to the built-in rand() function to return a number between 0 and 999-billion, and concatenating that result three times.
The path name might be known or guessed by an attacker, especially for applications known to be written using Dancer with standard installation locations.
The epoch time can be guessed by an attacker, and may be leaked in the HTTP header.
The process id comes from a small set of numbers, and workers may have sequential process ids.
The built-in rand() function is seeded with 32-bits and is considered unsuitable for security applications.
Predictable session ids could allow an attacker to gain access to systems.
| Weakness | CWE-338 : Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) |
|---|
Product status
Known affected
| Product | Score | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Dancer greater than 0 |
|
giterlizzi
Namespace: https://github.com/giterlizzi/
gdt@cpan.org
References
- CPANSA-Dancer-2026-5080 JSON self
https://raw.githubusercontent.com/giterlizzi/perl-CPANSA-CSAF/develop/csaf/white/2026/cpansa-dancer-2026-5080.json - https://metacpan.org/release/BIGPRESH/Dancer-1.3522/source/lib/Dancer/Session/Abstract.pm#L85-102 external
https://metacpan.org/release/BIGPRESH/Dancer-1.3522/source/lib/Dancer/Session/Abstract.pm#L85-102 - https://security.metacpan.org/patches/D/Dancer/1.3522/CVE-2026-5080-r1.patch external
https://security.metacpan.org/patches/D/Dancer/1.3522/CVE-2026-5080-r1.patch - http://www.openwall.com/lists/oss-security/2026/04/30/19 external
http://www.openwall.com/lists/oss-security/2026/04/30/19 - CVE-2026-5080 (NVD) external
https://nvd.nist.gov/vuln/detail/CVE-2026-5080
Revision history
| Version | Date of the revision | Summary of the revision |
|---|---|---|
| 1 | Thu Apr 30 00:00:00 2026 | First release |
Sharing rules
TLP:WHITE
For the TLP version see: https://www.first.org/tlp/