CVE-2026-43618

Description

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.

Why is this CVE high priority?

rsync developers have rated this as being a high severity issue

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References

• MITRE
• NVD
• Launchpad
• Debian

Related Ubuntu Security Notices (USN)

• USN-8283-1
• rsync vulnerabilities
• 20 May 2026
• USN-8349-1
• rsync vulnerabilities
• 1 June 2026

Other references

• https://www.cve.org/CVERecord?id=CVE-2026-43618
• https://github.com/RsyncProject/rsync/security/advisories/GHSA-g37v-g3gj-pmwq