CVE-2026-2597: Crypt::SysRandom::XS versions before 0.010 for Perl is vulnerable to a heap buffer overflow in the XS function random_bytes(). The function does not ...

Description

Crypt::SysRandom::XS versions before 0.010 for Perl is vulnerable to a heap buffer overflow in the XS function random_bytes(). The function does not validate that the length parameter is non-negative. If a negative value (e.g. -1) is supplied, the expression length + 1u causes an integer wraparound, resulting in a zero-byte allocation. The subsequent call to chosen random function (e.g. getrandom) passes the original negative value, which is implicitly converted to a large unsigned value (typically SIZE_MAX). This can result in writes beyond the allocated buffer, leading to heap memory corruption and application crash (denial of service). In common usage, the length argument is typically hardcoded by the caller, which reduces the likelihood of attacker-controlled exploitation. Applications that pass untrusted input to this parameter may be affected.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

0.29%

21.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions	Update
Leont	Crypt\	< 0.010	Sysrandom\

References

https://metacpan.org/dist/Crypt-SysRandom-XS/changesRelease Notes
https://metacpan.org/release/LEONT/Crypt-SysRandom-XS-0.011/source/lib/Crypt/SysRandom/XS.xs#L51-52Issue Tracking

Timeline

Published: Feb 27, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-2597?

Crypt::SysRandom::XS versions before 0.010 for Perl is vulnerable to a heap buffer overflow in the XS function random_bytes(). The function does not validate that the length parameter is non-negative. If a negative value (e.g. -1) is supplied, the expression length + 1u causes an integer wraparound, resulting in a zero-byte allocation. The subsequent call to chosen random function (e.g. getrandom) passes the original negative value, which is implicitly converted to a large unsigned value (typically SIZE_MAX). This can result in writes beyond the allocated buffer, leading to heap memory corruption and application crash (denial of service). In common usage, the length argument is typically hardcoded by the caller, which reduces the likelihood of attacker-controlled exploitation. Applications that pass untrusted input to this parameter may be affected.

How severe is CVE-2026-2597?

CVE-2026-2597 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.29% probability of exploitation in the next 30 days.

How do I fix CVE-2026-2597?

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.