CVE-2026-59139

CRITICALCVSS 9.1/10EPSS 0.16%

Last modified

CVE-2026-59139 is a critical-severity vulnerability rated 9.1/10 on the CVSS scale. 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.. EPSS estimates a 0.16% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
9.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

EPSS Probability
0.16%

5.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
EGORData::ReqRep::Shared< 0.05

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is 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. 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.
How severe is CVE-2026-59139?
CVE-2026-59139 has a CVSS score of 9.1/10 (CRITICAL severity). The EPSS model estimates a 0.16% probability of exploitation in the next 30 days.
How do I fix CVE-2026-59139?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST