CVE-2026-2597 Integer overflow in Crypt::SysRandom::XS
A heap buffer overflow in the Perl Crypt::SysRandom::XS library allows denial of service via integer overflow when handling negative length parameters.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-2597?
CVE-2026-2597 is a high-severity vulnerability in LEONT Crypt::SysRandom::XS, published on 26 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-2597?
It affects 1 product.
Products include Leont Crypt\.
How do I fix CVE-2026-2597?
Upgrade to a fixed version.
Is CVE-2026-2597 being exploited?
There is no known exploitation of CVE-2026-2597 in the wild and no public exploit code.
Other vulnerabilities in LEONT Crypt::SysRandom::XS
Sources
Also known as DEBIAN-CVE-2026-2597, GHSA-rpp6-x48q-7fq5, UBUNTU-CVE-2026-2597.