CVE-2026-116773 (GCVE-0-2026-116773)
Vulnerability from cvelistv5
Published
2026-10-27 20:23
Modified
2026-10-27 20:23
CWE
  • CWE-770 - Allocation of Resources Without Limits or Throttling
Summary
russh is a Rust SSH client and server library that includes an SSH agent protocol implementation. Prior to 0.65.0, the client Session::process_packet path in russh/src/client/encrypted.rs accepts repeated packets encoded with russh's private msg::EXT_INFO = 7 before authentication, while the standards-compliant EXT_INFO message number 82 does not reach the affected handler. The handle_ext_info function appends every parsed extension name to received_extensions without clearing, deduplicating, or bounding the vector. A malicious SSH server that deliberately sends private message number 7 can therefore retain an unbounded number of attacker-controlled extension names for the session lifetime, causing progressive client memory exhaustion. This issue is fixed in version 0.65.0.
Impacted products
Vendor Product Version
Eugeny russh Version: < 0.65.0
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Show details on NVD website


{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "russh",
          "vendor": "Eugeny",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.65.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "russh is a Rust SSH client and server library that includes an SSH agent protocol implementation. Prior to 0.65.0, the client Session::process_packet path in russh/src/client/encrypted.rs accepts repeated packets encoded with russh\u0027s private msg::EXT_INFO = 7 before authentication, while the standards-compliant EXT_INFO message number 82 does not reach the affected handler. The handle_ext_info function appends every parsed extension name to received_extensions without clearing, deduplicating, or bounding the vector. A malicious SSH server that deliberately sends private message number 7 can therefore retain an unbounded number of attacker-controlled extension names for the session lifetime, causing progressive client memory exhaustion. This issue is fixed in version 0.65.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 4.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-770",
              "description": "CWE-770: Allocation of Resources Without Limits or Throttling",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-27T20:23:47.305Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/Eugeny/russh/security/advisories/GHSA-4p9f-7p9m-5vfg",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/Eugeny/russh/security/advisories/GHSA-4p9f-7p9m-5vfg"
        },
        {
          "name": "https://github.com/Eugeny/russh/commit/b33e93beec393e6d29eee69c1b8831736724ee75",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/Eugeny/russh/commit/b33e93beec393e6d29eee69c1b8831736724ee75"
        },
        {
          "name": "https://github.com/Eugeny/russh/releases/tag/v0.65.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/Eugeny/russh/releases/tag/v0.65.0"
        }
      ],
      "source": {
        "advisory": "GHSA-4p9f-7p9m-5vfg",
        "discovery": "UNKNOWN"
      },
      "title": "russh\u0027s SSH client is susceptible to unbounded allocations via EXT_INFO packets"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-116773",
    "datePublished": "2026-10-27T20:23:25.559Z",
    "dateReserved": "2026-10-26T21:53:35.165Z",
    "dateUpdated": "2026-10-27T20:23:47.305Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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