KAZEBURO Plack::Middleware::Session::Simple up to 0.04 on Perl Default Session ID Generator rand generation of predictable numbers or identifiers

CVSS Meta Temp Score
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CTI Interest Score
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6.7$0-$5k0.00

Summaryinfo

A vulnerability was found in KAZEBURO Plack::Middleware::Session::Simple up to 0.04 on Perl. It has been classified as problematic. This impacts the function rand of the component Default Session ID Generator. Performing a manipulation results in generation of predictable numbers or identifiers. This vulnerability is known as CVE-2025-40926. Remote exploitation of the attack is possible. No exploit is available. Applying a patch is the recommended action to fix this issue.

Detailsinfo

A vulnerability classified as problematic has been found in KAZEBURO Plack::Middleware::Session::Simple up to 0.04 on Perl. This affects the function rand of the component Default Session ID Generator. The manipulation with an unknown input leads to a generation of predictable numbers or identifiers vulnerability. CWE is classifying the issue as CWE-340. The product uses a scheme that generates numbers or identifiers that are more predictable than required. This is going to have an impact on confidentiality. The summary by CVE is:

Plack::Middleware::Session::Simple versions before 0.05 for Perl generates session ids insecurely. The default session id generator returns a SHA-1 hash seeded with the built-in rand function, the epoch time, and the PID. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage. Predictable session ids could allow an attacker to gain access to systems. Plack::Middleware::Session::Simple is intended to be compatible with Plack::Middleware::Session, which had a similar security issue CVE-2025-40923.

The advisory is shared at metacpan.org. This vulnerability is uniquely identified as CVE-2025-40926 since 04/16/2025. The exploitability is told to be difficult. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1600.001 for this issue.

Applying the patch 760bb358b8f53e52cf415888a4ac858fd99bb24e is able to eliminate this problem. The bugfix is ready for download at github.com.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Vendor

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.7
VulDB Meta Temp Score: 6.7

VulDB Base Score: 3.7
VulDB Temp Score: 3.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

ADP CISA Base Score: 9.8
ADP CISA Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Generation of predictable numbers or identifiers
CWE: CWE-340 / CWE-331 / CWE-330
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: 760bb358b8f53e52cf415888a4ac858fd99bb24e

Timelineinfo

04/16/2025 CVE reserved
03/05/2026 +323 days Advisory disclosed
03/05/2026 +0 days VulDB entry created
03/12/2026 +7 days VulDB entry last update

Sourcesinfo

Advisory: metacpan.org
Status: Confirmed

CVE: CVE-2025-40926 (🔒)
GCVE (CVE): GCVE-0-2025-40926
GCVE (VulDB): GCVE-100-348885

Entryinfo

Created: 03/05/2026 07:14
Updated: 03/12/2026 01:40
Changes: 03/05/2026 07:14 (58), 03/06/2026 11:07 (11), 03/10/2026 18:07 (1), 03/12/2026 01:40 (1)
Complete: 🔍
Cache ID: 216::103

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