Vulnerability Report

CVE-2026-57432

Title: Integer overflow leading to OOB heap read in Perl pack/unpack

Memory Corruption

Proof Of Concept

No public PoC currently indexed for CVE-2026-57432.

CWE Category CWE-125

Published Date Jul 13, 2026

Modified Date Jul 14, 2026

Exploit Status Not Found

Score 8.4 CVSS v

Exploit Probability (EPSS)

0.20%

Vulnerability Summary

CVE-2026-57432: Perl versions through 5.43.10 have an integer overflow in S_measure_struct leading to an out-of-bounds heap read in pack and unpack. S_measure_struct adds each item's size times its repeat count to a running total with no overflow check, so a large repeat count in a pack or unpack template wraps the signed SSize_t total negative. The @, X, and x position codes then guard their moves with a signed length comparison that passes when the length is negative, advancing the buffer pointer out of bounds. A template derived from untrusted input can read heap memory past the buffer and return it to the caller.

Impacted Vendors

perl 1

larry_wall 1

Reference Links

https://github.com/Perl/perl5/commit/40754edc72dd3e513d758153c0e2f0215897740e.patch https://github.com/Perl/perl5/commit/5f7eb6bbbe0510964e3fb1d6bb691e5445913e55.patch

CVSS v3.1

Source Entity [email protected]

Severity HIGH

8.4

Attack Vector

LOCAL

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

UNCHANGED

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