CVE-2026-44507
Rsync: hostname/ACL bypass on DNS-lookup failure
Description
Rejected reason: ** REJECT ** DO NOT USE THIS CANDIDATE NUMBER. ConsultIDs: CVE-2026-43617. Reason: This candidate is a duplicate of CVE-2026-43617. Notes: All CVE users should reference CVE-2026-43617 instead of this candidate.
INFO
Published Date :
July 20, 2026, 9:16 p.m.
Last Modified :
July 21, 2026, 4:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Rsync to version 3.4.3.
- Verify daemon configuration after update.
- Ensure chroot contains necessary resolution files.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-44507 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-44507 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Rejected by [email protected]
Jul. 21, 2026
Action Type Old Value New Value -
CVE Modified by [email protected]
Jul. 21, 2026
Action Type Old Value New Value Changed Description Rsync is a file-copying tool that uses a delta-transfer algorithm to synchronize remote and local files. In versions prior to 3.4.3, when using a daemon configured with a chroot, the reverse DNS lookup of the connecting client was performed after the chroot had been entered. If the chroot did not contain the files glibc needs for resolution (/etc/resolv.conf, /etc/nsswitch.conf, /etc/hosts, NSS service modules), the lookup failed and the connecting hostname was set to "UNKNOWN". Hostname-based deny rules ("hosts deny = *.evil.example") therefore could not match, and an attacker who controlled the PTR record for their source IP could connect from a hostname that the administrator had intended to deny. IP-based ACLs ("hosts allow = 10.0.0.0/8") are unaffected. This issue is fixed in version 3.4.3. Rejected reason: ** REJECT ** DO NOT USE THIS CANDIDATE NUMBER. ConsultIDs: CVE-2026-43617. Reason: This candidate is a duplicate of CVE-2026-43617. Notes: All CVE users should reference CVE-2026-43617 instead of this candidate. Removed CVSS V3.1 GitHub, Inc.: AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Removed CWE GitHub, Inc.: CWE-863 Removed Reference GitHub, Inc.: https://github.com/RsyncProject/rsync/security/advisories/GHSA-rjfm-3w2m-jf4f Removed Affected [{'vendor': 'RsyncProject', 'product': 'rsync', 'versions': [{'status': 'affected', 'version': '< 3.4.3'}]}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 21, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-44507', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-21T12:50:29.635098Z'} -
New CVE Received by [email protected]
Jul. 20, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'RsyncProject', 'product': 'rsync', 'versions': [{'status': 'affected', 'version': '< 3.4.3'}]}] Added Description Rsync is a file-copying tool that uses a delta-transfer algorithm to synchronize remote and local files. In versions prior to 3.4.3, when using a daemon configured with a chroot, the reverse DNS lookup of the connecting client was performed after the chroot had been entered. If the chroot did not contain the files glibc needs for resolution (/etc/resolv.conf, /etc/nsswitch.conf, /etc/hosts, NSS service modules), the lookup failed and the connecting hostname was set to "UNKNOWN". Hostname-based deny rules ("hosts deny = *.evil.example") therefore could not match, and an attacker who controlled the PTR record for their source IP could connect from a hostname that the administrator had intended to deny. IP-based ACLs ("hosts allow = 10.0.0.0/8") are unaffected. This issue is fixed in version 3.4.3. Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Added CWE CWE-863 Added Reference https://github.com/RsyncProject/rsync/security/advisories/GHSA-rjfm-3w2m-jf4f