Vulnerability-Lookup

OESA-2026-2551 (CVE-2026-43620)

Vulnerability from osv_openeuler – Published: 2026-06-05 11:11 – Updated: 2026-08-06 11:11 – Source website

Summary

rsync security update

Details

Rsync is an open source utility that provides fast incremental file transfer. It uses the "rsync algorithm" which provides a very fast method for bringing remote files into sync. It does this by sending just the differences in the files across the link, without requiring that both sets of files are present at one of the ends of the link beforehand.

Security Fix(es):

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.(CVE-2026-43620)

Severity

5.5 (Medium)


                    
                      CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

References

URL

Type

	https://www.openeuler.org/zh/security/security-bu…	ADVISORY
	https://nvd.nist.gov/vuln/detail/CVE-2026-43620	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "aarch64": [
          "rsync-3.2.5-8.oe2203sp4.aarch64.rpm",
          "rsync-debuginfo-3.2.5-8.oe2203sp4.aarch64.rpm",
          "rsync-debugsource-3.2.5-8.oe2203sp4.aarch64.rpm"
        ],
        "noarch": [
          "rsync-help-3.2.5-8.oe2203sp4.noarch.rpm"
        ],
        "src": [
          "rsync-3.2.5-8.oe2203sp4.src.rpm"
        ],
        "x86_64": [
          "rsync-3.2.5-8.oe2203sp4.x86_64.rpm",
          "rsync-debuginfo-3.2.5-8.oe2203sp4.x86_64.rpm",
          "rsync-debugsource-3.2.5-8.oe2203sp4.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:22.03-LTS-SP4",
        "name": "rsync",
        "purl": "pkg:rpm/openEuler/rsync\u0026distro=openEuler-22.03-LTS-SP4"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.2.5-8.oe2203sp4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "severity": "Medium"
  },
  "details": "Rsync is an open source utility that provides fast incremental file transfer. It uses the \u0026amp;quot;rsync algorithm\u0026amp;quot; which provides a very fast method for bringing remote files into sync. It does this by sending just the differences in the files across the link, without requiring that both sets of files are present at one of the ends of the link beforehand.\r\n\r\nSecurity Fix(es):\n\nRsync version\u00a03.4.2 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.(CVE-2026-43620)",
  "id": "OESA-2026-2551",
  "modified": "2026-08-06T11:11:29Z",
  "published": "2026-06-05T11:11:29Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-2551"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43620"
    }
  ],
  "schema_version": "1.7.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "rsync security update",
  "upstream": [
    "CVE-2026-43620"
  ]
}

CVE-2026-43620 (GCVE-0-2026-43620)

Vulnerability from cvelistv5 – Published: 2026-05-20 00:47 – Updated: 2026-07-14 20:01

Title

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

Summary

Severity

6.9 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

6.5 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-05-20 14:11 UTC

CWE

CWE-125 - Out-of-bounds Read

Assigner

VulnCheck mitre root

References

3 references

URL	Tags
https://github.com/RsyncProject/rsync/security/ad…	vendor-advisory
https://github.com/RsyncProject/rsync/releases/ta…	release-notes
https://www.vulncheck.com/advisories/rsync-out-of…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
RsyncProject	rsync	Affected: 0 , < 3.4.3 (semver) cpe:2.3:a:samba:rsync::::::::

Date Public

2026-05-19 00:00

Credits

Pratham Gupta (@alchemy1729)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-43620",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-20T14:11:42.448773Z",
                "version": "2.0.3"
              },
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        "providerMetadata": {
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          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
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    ],
    "cna": {
      "affected": [
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          "defaultStatus": "unaffected",
          "packageURL": "pkg:github/RsyncProject/rsync",
          "product": "rsync",
          "repo": "https://github.com/RsyncProject/rsync",
          "vendor": "RsyncProject",
          "versions": [
            {
              "lessThan": "3.4.3",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:samba:rsync:*:*:*:*:*:*:*:*",
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        }
      ],
      "metrics": [
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            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
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            "attackVector": "NETWORK",
            "baseScore": 6.9,
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            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "ACTIVE",
            "valueDensity": "NOT_DEFINED",
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            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
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            "version": "3.1"
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          "scenarios": [
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              "lang": "en",
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      "problemTypes": [
        {
          "descriptions": [
            {
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      "providerMetadata": {
        "dateUpdated": "2026-07-14T20:01:07.518Z",
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      "references": [
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          "tags": [
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          "url": "https://github.com/RsyncProject/rsync/security/advisories/GHSA-28pw-r563-rxvm"
        },
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          "url": "https://github.com/RsyncProject/rsync/releases/tag/v3.4.3"
        },
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          "url": "https://www.vulncheck.com/advisories/rsync-out-of-bounds-array-read-via-recv-files"
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      "source": {
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    "datePublished": "2026-05-20T00:47:57.086Z",
    "dateReserved": "2026-05-01T18:22:45.639Z",
    "dateUpdated": "2026-07-14T20:01:07.518Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.