CVE-2026-44509

Arbitrary metadata modification via symlink races

Published Jul 20, 2026 · Updated Jul 20, 2026

TOCTOU symlink races in Rsync Project rsync before 3.4.3 allow local users to alter metadata outside an exported daemon module. set_file_attrs and finish_transfer invoke path-based chmod, lchown, utimes, rename, and related calls after attacker-controlled paths can change. The rejected identifier duplicates CVE-2026-43619; exploitation requires local filesystem access and a daemon configured with use chroot = no.

CVSS severity6.3
Medium
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

TOCTOU symlink races in Rsync Project rsync before 3.4.3 allow local users to alter metadata outside an exported daemon module. set_file_attrs and finish_transfer invoke path-based chmod, lchown, utimes, rename, and related calls after attacker-controlled paths can change. The rejected identifier duplicates CVE-2026-43619; exploitation requires local filesystem access and a daemon configured with use chroot = no.

The record

CVE
CVE-2026-44509
Published
Jul 20, 2026
Updated
Jul 20, 2026
Vendor
Rsync Project
Product
rsync
Classifications
CWE-367, CWE-59, CWE-863, T1222.002
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.4.3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Rsync Project · rsyncversion=< 3.4.3

Published CVSS scores

6.3GitHubCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
CWE-59Improper Link Resolution Before File Access ('Link Following')
CWE-863Incorrect Authorization
T1222.002Linux and Mac File and Directory Permissions Modification

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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