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Fencer Vulns
high 7.8

CVE-2026-29518 json

Rsync < 3.4.3 TOCTOU Race Condition Allows Symlink-Based Arbitrary File Write

published 2026-05-20 5 mo ago modified 2026-11-08 24 h ago also EUVD-2026-31100 , GHSA-pfv9-gp3h-73xv , JLSEC-2026-626

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

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.

Patch / fix

  • julia rsync_jll 3.4.4+0
  • RsyncProject rsync 3.4.3
  • Red Hat Red Hat Enterprise Linux 10 0:3.4.4-1.el10_2
  • Red Hat Red Hat Enterprise Linux 8 0:3.1.3-27.el8_10
  • Red Hat Red Hat Enterprise Linux 9 0:3.2.5-7.el9_8.2
  • Red Hat Red Hat OpenShift Container Platform 4.22 4.22.9.8.202608130832-0
  • Red Hat Red Hat Discovery 2 1782166952
  • rsync Debian 12 3.2.7-1+deb12u5
  • rsync Debian 13 3.4.1+ds1-5+deb13u3
  • rsync Debian 14 3.4.3+ds1-1

debian advisories DEBIAN-CVE-2026-29518

  • rsync Ubuntu 22.04 LTS 3.2.7-0ubuntu0.22.04.6
  • rsync Ubuntu 24.04 LTS 3.2.7-1ubuntu1.4
  • rsync Ubuntu 25.10 3.4.1+ds1-5ubuntu1.2
  • rsync Ubuntu 26.04 LTS 3.4.1+ds1-7ubuntu0.2
  • rsync Ubuntu Pro 14.04 LTS 3.1.0-2ubuntu0.4+esm3
  • rsync Ubuntu Pro 16.04 LTS 3.1.1-3ubuntu1.3+esm5
  • rsync Ubuntu Pro 18.04 LTS 3.1.2-2.1ubuntu1.6+esm3
  • rsync Ubuntu Pro 20.04 LTS 3.1.3-8ubuntu0.9+esm1

ubuntu advisories UBUNTU-CVE-2026-29518

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • rsync RHEL 9 3.2.5-7.el9_8.2
  • rsync-daemon RHEL 9 3.2.5-7.el9_8.2
  • rsync-rrsync RHEL 9 3.2.5-7.el9_8.2
  • rsync RHEL 8 3.1.3-27.el8_10
  • rsync-daemon RHEL 8 3.1.3-27.el8_10
  • rsync RHEL 10.2 3.4.4-1.el10_2
  • rsync-daemon RHEL 10.2 3.4.4-1.el10_2
  • rsync-rrsync RHEL 10.2 3.4.4-1.el10_2

red hat advisories RHSA-2026:26410RHSA-2026:26408RHSA-2026:26332

  • rsync SLES for SAP applications 16.0, SLES 16.0 3.4.1-160000.4.1
  • rsync SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 3.1.3-3.46.1

suse advisories SUSE-SU-2026:3629-1SUSE-SU-2026:22015-1

  • rsync openSUSE Tumbleweed 3.4.3-1.1

opensuse advisories openSUSE-SU-2026:10857-1

  • rsync AlmaLinux 10 3.4.4-1.el10_2
  • rsync-daemon AlmaLinux 10 3.4.4-1.el10_2
  • rsync-rrsync AlmaLinux 10 3.4.4-1.el10_2
  • rsync AlmaLinux 8 3.1.3-27.el8_10
  • rsync-daemon AlmaLinux 8 3.1.3-27.el8_10
  • rsync AlmaLinux 9 3.2.5-7.el9_8.2
  • rsync-daemon AlmaLinux 9 3.2.5-7.el9_8.2
  • rsync-rrsync AlmaLinux 9 3.2.5-7.el9_8.2

almalinux advisories ALSA-2026:26332ALSA-2026:26408ALSA-2026:26410

  • rsync Rocky Linux 10 3.4.4-1.el10_2
  • rsync Rocky Linux 9 3.2.5-7.el9_8.2
  • rsync Rocky Linux 8 3.1.3-27.el8_10

rocky linux advisories RLSA-2026:26332RLSA-2026:26410RLSA-2026:26408

  • rsync Alpine 3.24, Alpine 3.23, Alpine 3.22 +2 more 3.4.3-r0

alpine advisories ALPINE-CVE-2026-29518

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • rsync Azure Linux 3.0 3.4.3-1

azure linux advisories AZL-87012

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-29518 updated cvss 7.8

rsync: TOCTOU symlink race condition allowing local privilege escalation in daemon mode without chroot.

  • Red Hat Enterprise Linux 6 rsync Red Hat Enterprise Linux 7 rsync Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: workaround, no fix available
  • Red Hat Discovery 2 discovery/discovery-ui-rhel9 1782166952
    fixed: vendor fix RHSA-2026:29197
  • Red Hat Enterprise Linux AppStream (v. 9) rsync-daemon 3.2.5-7.el9_8.2, rsync-rrsync 3.2.5-7.el9_8.2
    fixed: vendor fix RHSA-2026:26410
  • Red Hat Enterprise Linux AppStream (v. 10) rsync-daemon 3.4.4-1.el10_2, rsync-rrsync 3.4.4-1.el10_2
    fixed: vendor fix RHSA-2026:26332
  • Red Hat Enterprise Linux BaseOS (v. 8) rsync 3.1.3-27.el8_10, rsync-daemon 3.1.3-27.el8_10
    fixed: vendor fix RHSA-2026:26408
  • Red Hat Enterprise Linux BaseOS (v. 9) rsync 3.2.5-7.el9_8.2
    fixed: vendor fix RHSA-2026:26410
  • Red Hat Enterprise Linux BaseOS (v. 10) rsync 3.4.4-1.el10_2
    fixed: vendor fix RHSA-2026:26332
  • Red Hat OpenShift Container Platform 4.22 rhcos 4.22.9.8.202608130832
    fixed: vendor fix RHSA-2026:54769
show 1 more
  • Red Hat Discovery 2 discovery/discovery-server-rhel9 1782159791
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
5 mo ago

Exploit prediction

0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 7.3 CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA 3.1 7.0 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
CISA ADP 3.1 7.8 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
CNA 4.0 7.3 CVSS: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
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
OSV 3.1 7.0 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
julia rsync_jll
<3.4.4+0
3.4.4+0

Affected products

  • RsyncProject rsync
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat OpenShift Container Platform 4.22
  • Red Hat Red Hat Discovery 2
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7

Classification

Weakness
  • CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.