EUVD-2026-37926
GHSA-3m67-fq74-f4qg
Severity by source
Sources disagree (Medium–Critical)AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Predicting SHA-1 from epoch, PID, and heap address requires offline computation and timing correlation, raising AC to H; session forgery enables both read and limited write of session state.
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CVSS VectorVendor: CPANSec
Lifecycle Timeline
2DescriptionCVE.org
Mojolicious::Sessions::Storable versions through 0.05 for Perl generate session ids insecurely.
The default session id generator returns a SHA-1 hash seeded with the built-in rand function, the epoch time, the heap address of an anonymous hash, and the PID.
These are predictable or low-entropy sources that are unsuitable for security purposes.
AnalysisAI
Predictable session ID generation in Mojolicious::Sessions::Storable through version 0.05 for Perl exposes applications to session hijacking. The default session ID generator computes a SHA-1 hash seeded exclusively with low-entropy, attacker-observable sources - Perl's built-in rand function, Unix epoch time, a heap address, and the process ID - none of which meet cryptographic unpredictability requirements for session tokens. No public exploit or active exploitation has been identified (EPSS 0.27%, 19th percentile; not in CISA KEV), but the flaw is automatable per CISA SSVC, meaning a scripted attacker can systematically enumerate candidate session IDs without complex per-target tuning.
Technical ContextAI
The affected component is Mojolicious::Sessions::Storable (CPE: cpe:2.3:a:hayajo:mojolicious::sessions::storable:*:*:*:*:*:*:*:*), a CPAN plugin for the Mojolicious Perl web framework that serializes and stores session data. The root cause is CWE-340 (Generation of Predictable Numbers or Identifiers): SHA-1 is used as a hash function, not a CSPRNG, and its output is only as random as its inputs. Perl's rand() is a deterministic PRNG seeded from the system clock; epoch time and PID are both low-cardinality values guessable within narrow windows; and heap addresses, while partially randomized by ASLR, provide far less entropy than a true random source. An attacker who can observe or approximate request timing can dramatically reduce the search space for valid session tokens. The CPANSec advisory cross-references their own guidance on secure random data for Perl at security.metacpan.org, and a companion CVE (CVE-2025-40923) appears related, suggesting a broader pattern in this library family.
RemediationAI
A vendor-supplied patch is available from CPANSec at https://security.metacpan.org/patches/M/Mojolicious-Plugin-SessionStore/0.05/CVE-2026-9692-r1.patch; this is a patch file against version 0.05, and a fully released post-0.05 package version on CPAN has not been independently confirmed from the available data - check metacpan.org/dist/Mojolicious-Plugin-SessionStore for the latest published release before applying the raw patch. As an immediate compensating control, override the default session ID generator with a cryptographically secure alternative: replace the SHA-1/rand-based generator with one sourced from Perl's Crypt::URandom or equivalent OS-level CSPRNG (/dev/urandom). Disabling session persistence entirely is an extreme but effective fallback if the module cannot be patched and an alternative session backend (e.g., Mojolicious::Plugin::Session with a secure generator) can be substituted. Invalidating all current sessions after patching is advisable, as previously issued IDs were generated insecurely. The CPANSec guidance at https://security.metacpan.org/docs/guides/random-data-for-security.html provides Perl-specific remediation patterns.
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View allVendor StatusVendor
SUSE
Severity: CriticalShare
External POC / Exploit Code
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