Vulnerability · Published Jul 21, 2026 · Assigned by CPANSec
CVE-2026-59139Data::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
Critical 9.1
In plain English
A critical-severity out-of-bounds read in Data::ReqRep::Shared from EGOR. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 46% of all known vulnerabilities).
Official 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 (as reported)
| Vendor | Product | Versions |
|---|---|---|
| EGOR | Data::ReqRep::Shared | 0 – before 0.05 |
Weakness: CWE-125 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H