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: 0.3%CVSS: 4.8Exploit: None knownExposed services: Not assessed

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
4.8MEDIUMmedium confidence
EG Risk
22
EG Risk 22/100

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%
EPSS PROB
0.3%
EPSS %ILE
22nd
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
githubMentions a patch (unverified)

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 / EcosystemFix (by version range) / 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 rangeFix by version rangeDependents
rsync—
  • every version up to 3.4.3-r0: fixed in 3.4.3-r0
—
Alpine:v3.21(1)
PackageVulnerable rangeFix by version rangeDependents
rsync—
  • every version up to 3.4.3-r0: fixed in 3.4.3-r0
—
Alpine:v3.22(1)
PackageVulnerable rangeFix by version rangeDependents
rsync—
  • every version up to 3.4.3-r0: fixed in 3.4.3-r0
—
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
rsync—
  • every version up to 3.4.3-r0: fixed in 3.4.3-r0
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
rsync—
  • every version up to 3.4.3-r0: fixed in 3.4.3-r0
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
rsync3.2.3-4, 3.2.3-4+deb11u1, 3.2.3-4+deb11u2, 3.2.3-4+deb11u3
  • every version up to 3.2.3-4+deb11u4: fixed in 3.2.3-4+deb11u4
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
rsync3.2.7-1, 3.2.7-1+deb12u1, 3.2.7-1+deb12u2, 3.2.7-1+deb12u3, 3.2.7-1+deb12u4
  • every version up to 3.2.7-1+deb12u5: fixed in 3.2.7-1+deb12u5
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
rsync3.4.1+ds1-5, 3.4.1+ds1-5+deb13u1, 3.4.1+ds1-5+deb13u2
  • every version up to 3.4.1+ds1-5+deb13u3: fixed in 3.4.1+ds1-5+deb13u3
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
rsync3.4.1+ds1-5 ... 3.4.2+ds1-2 (6 versions)
  • every version up to 3.4.3+ds1-1: fixed in 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 7× in last 7d / 24× 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 247 total refreshes for this CVE.

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

Related CVEs(same product + same vendor + same CWE)

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 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 0.3% probability of exploitation in the next 30 days (22nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-43617?
CVE-2026-43617 has a CVSS base score of 4.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-43617?
A fix for CVE-2026-43617 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-43617 are linked in the Vendor Advisories panel on this page.

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