CVE-2026-43617

MEDIUMPre-NVD 4.84.8—
EchelonGraph scoreMEDIUM confidence

Score 4.8 from GitHub Security Advisory published 2026-05-20. a secondary CVSS source baseline 4.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
4.8EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.8Exploit: None knownExposed: 0

A fix is available — apply it.

Rsync version 3.4.2 and prior contain an authorization bypass vulnerability in the rsync daemon's hostname-based access control list enforcement when configured with chroot. Attackers can bypass hostname-based deny rules by controlling the PTR record for their source IP address, allowing connections from hostnames that administrators intended to deny when reverse DNS resolution fails and defaults to UNKNOWN.

CVSS v3
4.8
EG Score
4.8(medium)
EG Risk
22(Track)
EG Risk 22/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity48% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
21%
KEV
Not listed

Published

May 20, 2026

Last Modified

July 24, 2026

Advisory Details (3)

Auto-updated May 20, 2026
Patch available. Sources: github.
generic

Rsync < 3.4.3 Authorization Bypass via Hostname Resolution | Advisories | VulnCheck

https://www.vulncheck.com/advisories/rsync-authorization-bypass-via-hostname-resolution
github Patch Available

rsync: hostname/ACL bypass on DNS-lookup failure · Advisory · RsyncProject/rsync · GitHub

https://github.com/RsyncProject/rsync/security/advisories/GHSA-rjfm-3w2m-jf4f
generic

Release v3.4.3 · RsyncProject/rsync · GitHub

https://github.com/RsyncProject/rsync/releases/tag/v3.4.3

Vendor Advisories for CVE-2026-43617(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntursync (3.4.1+ds1-5ubuntu1.2) @ questing2026-08-23ubuntu
ubuntursync (3.1.1-3ubuntu1.3+esm5) @ xenial2026-08-23ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(9 across 9 ecosystems)
Alpine:v3.20(1)
PackageVulnerable rangeFixed inDependents
rsync—3.4.3-r0—
Alpine:v3.21(1)
PackageVulnerable rangeFixed inDependents
rsync—3.4.3-r0—
Alpine:v3.22(1)
PackageVulnerable rangeFixed inDependents
rsync—3.4.3-r0—
Alpine:v3.23(1)
PackageVulnerable rangeFixed inDependents
rsync—3.4.3-r0—
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
rsync—3.4.3-r0—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
rsync3.2.3-4, 3.2.3-4+deb11u1, 3.2.3-4+deb11u2, 3.2.3-4+deb11u33.2.3-4+deb11u4—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
rsync3.2.7-1, 3.2.7-1+deb12u1, 3.2.7-1+deb12u2, 3.2.7-1+deb12u3, 3.2.7-1+deb12u43.2.7-1+deb12u5—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
rsync3.4.1+ds1-5, 3.4.1+ds1-5+deb13u1, 3.4.1+ds1-5+deb13u23.4.1+ds1-5+deb13u3—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
rsync3.4.1+ds1-5 ... 3.4.2+ds1-2 (6 versions)3.4.3+ds1-1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(2)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 6× in last 7d / 34× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 233 total refreshes for this CVE.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-17 19:31 UTCEPSS rescore
  3. 2026-09-16 14:08 UTCEPSS rescore
  4. 2026-09-16 05:15 UTCEPSS rescore
  5. 2026-09-13 16:47 UTCEPSS rescore
  6. 2026-09-12 15:01 UTCEPSS rescore
  7. 2026-09-11 14:53 UTCEPSS rescore
  8. 2026-09-11 09:37 UTCEPSS rescore
  9. 2026-09-11 05:23 UTCOSV refresh
  10. 2026-09-10 09:34 UTCEPSS rescore
  11. 2026-09-08 22:00 UTCEPSS rescore
  12. 2026-09-07 16:01 UTCEPSS rescore
  13. 2026-09-06 13:47 UTCEPSS rescore
  14. 2026-09-04 05:06 UTCEPSS rescore
  15. 2026-09-02 14:12 UTCEPSS rescore
  16. 2026-09-01 13:54 UTCEPSS rescore
  17. 2026-08-30 19:17 UTCEPSS rescore
  18. 2026-08-30 01:22 UTCEPSS rescore
  19. 2026-08-28 21:41 UTCEPSS rescore
  20. 2026-08-27 14:25 UTCEPSS rescore
  21. 2026-08-26 14:46 UTCEPSS rescore
  22. 2026-08-25 13:49 UTCEPSS rescore
  23. 2026-08-23 16:58 UTCEG score recompute
  24. 2026-08-23 16:58 UTCVendor advisory
  25. 2026-08-23 16:58 UTCGHSA enrichment
Show 75 more
  1. 2026-08-23 00:19 UTCEPSS rescore
  2. 2026-08-21 23:49 UTCEPSS rescore
  3. 2026-08-21 23:35 UTCEG score recompute
  4. 2026-08-21 23:35 UTCVendor advisory
  5. 2026-08-21 23:35 UTCGHSA enrichment
  6. 2026-08-20 22:55 UTCEPSS rescore
  7. 2026-08-20 18:57 UTCEG score recompute
  8. 2026-08-20 18:57 UTCVendor advisory
  9. 2026-08-20 18:57 UTCGHSA enrichment
  10. 2026-08-19 17:04 UTCEPSS rescore
  11. 2026-08-18 13:48 UTCEPSS rescore
  12. 2026-08-17 13:47 UTCEPSS rescore
  13. 2026-08-17 09:57 UTCEG score recompute
  14. 2026-08-17 09:57 UTCVendor advisory
  15. 2026-08-17 09:57 UTCGHSA enrichment
  16. 2026-08-16 14:56 UTCEPSS rescore
  17. 2026-08-16 03:32 UTCEG score recompute
  18. 2026-08-16 03:32 UTCVendor advisory
  19. 2026-08-16 03:32 UTCGHSA enrichment
  20. 2026-08-16 02:14 UTCEPSS rescore
  21. 2026-08-15 01:30 UTCEPSS rescore
  22. 2026-08-15 00:58 UTCVendor advisory
  23. 2026-08-15 00:58 UTCGHSA enrichment
  24. 2026-08-14 02:04 UTCEG score recompute
  25. 2026-08-14 02:04 UTCVendor advisory
  26. 2026-08-14 02:04 UTCGHSA enrichment
  27. 2026-08-13 22:00 UTCEPSS rescore
  28. 2026-08-12 22:25 UTCEG score recompute
  29. 2026-08-12 22:25 UTCVendor advisory
  30. 2026-08-12 22:25 UTCGHSA enrichment
  31. 2026-08-12 13:51 UTCEPSS rescore
  32. 2026-08-11 23:31 UTCEG score recompute
  33. 2026-08-11 23:31 UTCVendor advisory
  34. 2026-08-11 23:31 UTCGHSA enrichment
  35. 2026-08-11 13:43 UTCEPSS rescore
  36. 2026-08-11 00:37 UTCEG score recompute
  37. 2026-08-11 00:37 UTCVendor advisory
  38. 2026-08-11 00:37 UTCGHSA enrichment
  39. 2026-08-11 00:00 UTCEPSS rescore
  40. 2026-08-10 00:28 UTCEG score recompute
  41. 2026-08-10 00:28 UTCVendor advisory
  42. 2026-08-10 00:28 UTCGHSA enrichment
  43. 2026-08-09 13:46 UTCEPSS rescore
  44. 2026-08-09 01:34 UTCEG score recompute
  45. 2026-08-09 01:34 UTCVendor advisory
  46. 2026-08-09 01:34 UTCGHSA enrichment
  47. 2026-08-08 16:37 UTCEPSS rescore
  48. 2026-08-07 19:08 UTCEG score recompute
  49. 2026-08-07 19:08 UTCVendor advisory
  50. 2026-08-07 19:08 UTCGHSA enrichment
  51. 2026-08-06 20:14 UTCEG score recompute
  52. 2026-08-06 20:14 UTCVendor advisory
  53. 2026-08-06 20:14 UTCGHSA enrichment
  54. 2026-08-06 13:46 UTCEPSS rescore
  55. 2026-08-05 21:20 UTCEG score recompute
  56. 2026-08-05 21:20 UTCVendor advisory
  57. 2026-08-05 21:20 UTCGHSA enrichment
  58. 2026-08-05 19:17 UTCEPSS rescore
  59. 2026-08-04 15:10 UTCEPSS rescore
  60. 2026-08-04 10:38 UTCEPSS rescore
  61. 2026-08-03 16:56 UTCEG score recompute
  62. 2026-08-03 16:56 UTCVendor advisory
  63. 2026-08-03 16:56 UTCGHSA enrichment
  64. 2026-08-03 10:36 UTCEPSS rescore
  65. 2026-08-02 16:43 UTCEG score recompute
  66. 2026-08-02 16:43 UTCVendor advisory
  67. 2026-08-02 16:43 UTCGHSA enrichment
  68. 2026-08-02 02:27 UTCEPSS rescore
  69. 2026-08-01 17:49 UTCEG score recompute
  70. 2026-08-01 17:49 UTCVendor advisory
  71. 2026-08-01 17:49 UTCGHSA enrichment
  72. 2026-08-01 04:16 UTCEPSS rescore
  73. 2026-07-30 16:28 UTCEPSS rescore
  74. 2026-07-30 01:30 UTCEPSS rescore
  75. 2026-07-28 15:36 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-43617?
CVE-2026-43617 is a medium vulnerability published on May 20, 2026. Rsync version 3.4.2 and prior contain an authorization bypass vulnerability in the rsync daemon's hostname-based access control list enforcement when configured with chroot. Attackers can bypass hostname-based deny rules by controlling the PTR record for their source IP address, allowing…
When was CVE-2026-43617 disclosed?
CVE-2026-43617 was first published in the National Vulnerability Database on May 20, 2026, with the most recent update on July 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43617 actively exploited?
CVE-2026-43617 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 79.1% of all scored CVEs.
What is the CVSS score of CVE-2026-43617?
CVE-2026-43617 has a CVSS v3 base score of 4.8 (NVD).
How do I remediate CVE-2026-43617?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43617, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-43617

Explore →

Is Your Infrastructure Affected by CVE-2026-43617?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs