CVE-2026-59139
Deferred Deferred - Pending Action

Out-of-Bounds Read in Data::ReqRep::Shared Perl Module

Publication date: 2026-07-21

Last updated on: 2026-07-21

Assigner: CPANSec

Description
Data::ReqRep::Shared versions before 0.05 for Perl allow an out-of-bounds read via an unvalidated arena offset and length in reqrep_recv_locked. The attach-time validator reqrep_validate_header checks the header scalars and region layout against the file size, but does not validate the array contents it then trusts. reqrep_recv_locked does memcpy(copy_buf, req_arena + arena_off, len) with arena_off and len read raw from the mmap'd segment and never bounded against the arena capacity (req_arena_cap). A local peer that can write the backing file can leave the header valid while poisoning a request slot's offset and length, so receiving the request copies a file-controlled offset and length out of the arena, reading adjacent memory or crashing the process.

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Meta Information

Published
2026-07-21
Last Modified
2026-07-21
Generated
2026-07-22
AI Q&A
2026-07-21
EPSS Evaluated
N/A
NVD
CVE-2026-59139
EUVD
EUVD-2026-46352

Affected Vendors & Products

Currently, no data is known.

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-125 The product reads data past the end, or before the beginning, of the intended buffer.

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Executive Summary

This vulnerability is an out-of-bounds read issue in the Perl module Data::ReqRep::Shared versions before 0.05. It occurs because the function reqrep_recv_locked performs a memcpy operation using unvalidated arena offset and length values read from a memory-mapped segment. The validator reqrep_validate_header checks header scalars and region layout but fails to validate array contents, trusting potentially malicious offset and length values. This allows a local attacker who can write to the backing file to manipulate these values, causing the process to read adjacent memory or crash.

Detection Guidance

This vulnerability involves an out-of-bounds read in Data::ReqRep::Shared versions before 0.05 for Perl. Detection requires checking installed Perl module versions and validating arena offset handling in reqrep_recv_locked. No direct commands are provided in the context to detect this issue.

Impact Analysis

If you use Data::ReqRep::Shared versions before 0.05, an attacker with local file write access could exploit this to read sensitive memory or crash your application. This could lead to information disclosure or denial-of-service conditions, depending on the context in which the module is used.

Compliance Impact

This vulnerability involves an out-of-bounds read due to unvalidated arena offsets and lengths in Perl's Data::ReqRep::Shared library. It could allow local attackers to read adjacent memory or crash processes by manipulating file-controlled offsets. This does not directly impact compliance with GDPR, HIPAA, or similar standards as it is a local privilege escalation issue rather than a data exposure or privacy violation.

Mitigation Strategies

Immediately update the Data::ReqRep::Shared Perl module to version 0.05 or later to address the out-of-bounds read vulnerability. Ensure all local peers with write access to backing files are trusted and cannot manipulate request slots.

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