CVE-2026-59139: 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

Severity: critical (CVSS 9.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-21 · updated 2026-10-24
Weakness: CWE-125

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.

Affected products

EGOR Data::ReqRep::Shared: before 0.05 — fixed in 0.05

How to fix

Upgrade to a fixed version: EGOR Data::ReqRep::Shared 0.05. Check the vendor advisory for mitigations.

References

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