CVE-2026-29518: rsyncproject rsync
Vulnerability summary
CVE-2026-29518 is a high (CVSS 7.3) vulnerability in rsyncproject rsync. EPSS estimates a 0.14% chance of exploitation in the next 30 days, higher than 3% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 7 · Related 7Timeline
- 20-05-2026PublishedVulnerability first disclosed.
- 01-09-2026Last modifiedVulnerability information updated.
Description
Rsync versions before 3.4.3 contain a time-of-check to time-of-use (TOCTOU) race condition in daemon file handling that allows attackers to redirect file writes outside intended directories by replacing parent directory components with symbolic links. Attackers with write access to a module path can exploit this race condition to create or overwrite arbitrary files, potentially modifying sensitive system files and achieving privilege escalation when the daemon runs with elevated privileges. This vulnerability can only be triggered if the chroot setting is false.
CVSS metrics
8 scores · 5 sources · 2 versions- OSV · AlpineEcosystem advisory · calculated7.3HighCVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- OSV · UbuntuEcosystem advisory · calculated7.3HighCVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- OSV · DebianEcosystem advisory · calculated7.3HighCVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- NVDNIST7.3HighCVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:HDiffers
- NVDNIST7.0HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.14%
Chance of exploitation in the next 30 days
Percentile
3%
Versus all other CVEs
30-day change
-0.01 pp
From 0.15% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Alpine1 product
- rsync< 3.4.3-r0
Debian1 product
- rsync< 3.2.7-1+deb12u5 | < 3.4.1+ds1-5+deb13u3 | < 3.4.3+ds1-1
Rsyncproject1 product
- rsync< 3.4.3
Samba1 product
- rsync< 3.4.3
Ubuntu1 product
- rsync< 3.1.0-2ubuntu0.4+esm3 | < 3.1.1-3ubuntu1.3+esm5 | < 3.1.2-2.1ubuntu1.6+esm3 | < 3.1.3-8ubuntu0.9+esm1 | < 3.2.7-0ubuntu0.22.04.6 | < 3.2.7-1ubuntu1.4 | < 3.4.1+ds1-5ubuntu1.2 | < 3.4.1+ds1-7ubuntu0.2
5 vendors · 5 products
References
21 links- github.com/RsyncProject/rsync/releases/tag/v3.4.3Release Notes
- michael.stapelberg.ch/posts/2026-05-24-minimal-memory-safe-go-rsync-vulns/Technical Description