CVE-2026-43620

MEDIUMNVD 5.56.5
EchelonGraph scoreMEDIUM confidence

“▲” beside the score: it is higher than NVD's CVSS score.

Score 6.5 from GitHub Security Advisory published 2026-05-20. NVD baseline CVSS 5.5; sources differ by 1.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
6.5EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 5.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Rsync version 3.4.2 and prior contain a receiver-side out-of-bounds array read vulnerability in recv_files() in receiver.c that allows a malicious rsync server to crash the rsync client process. Attackers can exploit the vulnerability by setting CF_INC_RECURSE in compatibility flags and sending a specially crafted file list where the first sorted entry is not the leading dot directory, followed by a transfer record with ndx=0 and an iflag word without ITEM_TRANSFER, causing the receiver to read 8 bytes before the allocated pointer array and dereference an invalid pointer at an unmapped address, resulting in a deterministic SIGSEGV crash of the rsync client.

CVSS v3
5.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
29
EG Risk 29/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity65% × 45%
Impact severity (EG Severity): CVSS 6.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.5% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.5%
EPSS %ILE
38th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (6.5): severity, escalated by confirmed exploitation. This CVE's 6.5 is its impact severity (EG Severity), not escalated.

EG Severity
6.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-17). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

May 20, 2026

Last Modified

July 24, 2026

Advisory Details (3)

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

Rsync < 3.4.3 Out-of-Bounds Array Read via recv_files() | Advisories | VulnCheck

https://www.vulncheck.com/advisories/rsync-out-of-bounds-array-read-via-recv-files
GitHub advisoryMentions a patch (unverified)

rsync: receiver-side out-of-bounds read enables remote DoS from malicious server · Advisory · RsyncProject/rsync · GitHub

https://github.com/RsyncProject/rsync/security/advisories/GHSA-28pw-r563-rxvm
Web page

Release v3.4.3 · RsyncProject/rsync · GitHub

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

Vendor Advisories for CVE-2026-43620(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 (3.1.0-2ubuntu0.4+esm3) @ trusty2026-08-23ubuntu
ubuntursync (3.4.1+ds1-7ubuntu0.2) @ resolute2026-08-23ubuntu

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 8× in last 7d / 29× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 263 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 163 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  2. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  3. 2026-10-18 03:40 UTCEG score recompute
  4. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  5. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  6. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  7. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  8. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  9. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  10. 2026-10-12 16:06 UTCEG score recompute
  11. 2026-10-11 19:48 UTCEG score recompute
  12. 2026-10-11 17:02 UTCEG score recompute
  13. 2026-10-11 14:28 UTCEG score recompute
  14. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  15. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  16. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  17. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  18. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  19. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  20. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  21. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  22. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  23. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  24. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  25. 2026-09-30 03:10 UTCOSV refresh
Show 75 more
  1. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  2. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  3. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  4. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  5. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  6. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  7. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  8. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  9. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  10. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  11. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  12. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  13. 2026-09-11 05:23 UTCOSV refresh
  14. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  15. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  16. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  17. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  18. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  19. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  20. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  21. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  22. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  23. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  24. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  25. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  26. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  27. 2026-08-23 16:58 UTCEG score recompute
  28. 2026-08-23 16:58 UTCVendor advisory
  29. 2026-08-23 16:58 UTCGHSA enrichmentGHSA-jmf6-74r8-6c28 · GitHub CVSS 6.5
  30. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  31. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  32. 2026-08-21 23:35 UTCEG score recompute
  33. 2026-08-21 23:35 UTCVendor advisory
  34. 2026-08-21 23:35 UTCGHSA enrichmentGHSA-jmf6-74r8-6c28 · GitHub CVSS 6.5
  35. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  36. 2026-08-20 18:57 UTCEG score recompute
  37. 2026-08-20 18:57 UTCVendor advisory
  38. 2026-08-20 18:57 UTCGHSA enrichmentGHSA-jmf6-74r8-6c28 · GitHub CVSS 6.5
  39. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  40. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  41. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  42. 2026-08-17 09:57 UTCEG score recompute
  43. 2026-08-17 09:57 UTCVendor advisory
  44. 2026-08-17 09:57 UTCGHSA enrichmentGHSA-jmf6-74r8-6c28 · GitHub CVSS 6.5
  45. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  46. 2026-08-16 03:32 UTCEG score recompute
  47. 2026-08-16 03:32 UTCVendor advisory
  48. 2026-08-16 03:32 UTCGHSA enrichmentGHSA-jmf6-74r8-6c28 · GitHub CVSS 6.5
  49. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  50. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  51. 2026-08-15 00:46 UTCVendor advisory
  52. 2026-08-15 00:46 UTCGHSA enrichmentGHSA-jmf6-74r8-6c28 · GitHub CVSS 6.5
  53. 2026-08-14 02:04 UTCEG score recompute
  54. 2026-08-14 02:04 UTCVendor advisory
  55. 2026-08-14 02:04 UTCGHSA enrichmentGHSA-jmf6-74r8-6c28 · GitHub CVSS 6.5
  56. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  57. 2026-08-12 22:00 UTCEG score recompute
  58. 2026-08-12 22:00 UTCVendor advisory
  59. 2026-08-12 22:00 UTCGHSA enrichmentGHSA-jmf6-74r8-6c28 · GitHub CVSS 6.5
  60. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  61. 2026-08-11 23:18 UTCEG score recompute
  62. 2026-08-11 23:18 UTCVendor advisory
  63. 2026-08-11 23:18 UTCGHSA enrichmentGHSA-jmf6-74r8-6c28 · GitHub CVSS 6.5
  64. 2026-08-11 13:43 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  65. 2026-08-11 00:37 UTCEG score recompute
  66. 2026-08-11 00:37 UTCVendor advisory
  67. 2026-08-11 00:37 UTCGHSA enrichmentGHSA-jmf6-74r8-6c28 · GitHub CVSS 6.5
  68. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  69. 2026-08-10 00:15 UTCEG score recompute
  70. 2026-08-10 00:15 UTCVendor advisory
  71. 2026-08-10 00:15 UTCGHSA enrichmentGHSA-jmf6-74r8-6c28 · GitHub CVSS 6.5
  72. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  73. 2026-08-09 01:34 UTCEG score recompute
  74. 2026-08-09 01:34 UTCVendor advisory
  75. 2026-08-09 01:34 UTCGHSA enrichmentGHSA-jmf6-74r8-6c28 · GitHub CVSS 6.5

Frequently asked(5)

What is CVE-2026-43620?
CVE-2026-43620 is a medium-severity vulnerability; its CVE record was published on May 20, 2026. Rsync version 3.4.2 and prior contain a receiver-side out-of-bounds array read vulnerability in recvfiles() in receiver.c that allows a malicious rsync server to crash the rsync client process. Attackers can exploit the vulnerability by setting CFINCRECURSE in compatibility flags and sending a…
When was CVE-2026-43620 made public?
CVE-2026-43620 was made public on May 19, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on May 20, 2026. EchelonGraph's copy of the record carries a last-modified date of July 24, 2026; the record at its source may have been updated since.
Is CVE-2026-43620 actively exploited?
CVE-2026-43620 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (38th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-43620?
CVE-2026-43620 has a CVSS v3 base score of 5.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 6.5 (MEDIUM).
How do I remediate CVE-2026-43620?
A fix for CVE-2026-43620 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-43620 are linked in the Vendor Advisories panel on this page.

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