PatchTheCVECVE-2026-59139: Data::ReqRep::Shared versions before 0.05 for Perl allow an out-of-bounds read via an unvalidated arena offset
CVE-2026-59139 is a critical-severity flaw (CVSS 9.1) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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 ne
Why this priority
- Critical severity
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.1 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.5% (top 55%) |
| CISA exploited list | No |
| Weakness | CWE-125 |
| Published | 2026-07-21 |
| Last modified | 2026-10-24 |
Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Exact fixes by distribution
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-59139?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-59139 being exploited?
CVE-2026-59139 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-59139 affect?
CVE-2026-59139 affects affected software. Severity is critical (CVSS 9.1). 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 a
How urgent is CVE-2026-59139?
Priority 48/100. Critical severity; Remotely exploitable, no login, no user action