Out-of-bounds Read in Rsyncproject Rsync

CVE-2026-43618

Rsync version 3.4.2 and prior contain an integer overflow vulnerability in the compressed-token decoder where a 32-bit signed counter is not checked for overflow, allowing a malicious sender to trigger an overflow that causes the receiver process to read and return data from outside the intended buffer bounds. Attackers can exploit this vulnerability to disclose process memory contents including environment variables, passwords, heap and stack data, and library memory pointers, significantly reducing ASLR effectiveness and facilitating further exploitation.

Vulnerability class: Buffer Overflow

EPSS: 0.008 (53.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-43618?
CVE-2026-43618 is a high-severity vulnerability in Rsyncproject Rsync, classified under Out-of-bounds Read. CVSS score: 8.1/10. Published 2026-05-20.
How severe is CVE-2026-43618?
High severity. CVSS v3 base score is 8.1 out of 10.