FKIE_CVE-2026-102821

Vulnerability from fkie_nvd - Published: 2026-09-29 19:17 - Updated: 2026-09-30 20:17
Severity
6.5 (Medium) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Summary
Russh is a Rust SSH client and server library. Prior to 0.63.2, an authenticated remote peer can send SSH_MSG_KEXINIT without the required SSH_MSG_KEX_ECDH_INIT and then flood SSH_MSG_CHANNEL_OPEN messages while SessionKexState::InProgress prevents priority_receiver in russh/src/server/session.rs from being drained. The server continues processing network input and enqueues a ChannelOpenReply for each request on an unbounded channel, allowing one connection to grow memory until the process is terminated. This issue is fixed in version 0.63.2.
References
security-advisories@github.comhttps://github.com/Eugeny/russh/commit/a282af361ac99bc76b80876d1aae128e89dbf66b
security-advisories@github.comhttps://github.com/Eugeny/russh/releases/tag/v0.63.2
security-advisories@github.comhttps://github.com/Eugeny/russh/security/advisories/GHSA-35g8-35p8-c8fw
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/Eugeny/russh/security/advisories/GHSA-35g8-35p8-c8fw
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "russh",
          "vendor": "Eugeny",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.63.2"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Russh is a Rust SSH client and server library. Prior to 0.63.2, an authenticated remote peer can send SSH_MSG_KEXINIT without the required SSH_MSG_KEX_ECDH_INIT and then flood SSH_MSG_CHANNEL_OPEN messages while SessionKexState::InProgress prevents priority_receiver in russh/src/server/session.rs from being drained. The server continues processing network input and enqueues a ChannelOpenReply for each request on an unbounded channel, allowing one connection to grow memory until the process is terminated. This issue is fixed in version 0.63.2."
    }
  ],
  "id": "CVE-2026-102821",
  "lastModified": "2026-09-30T20:17:23.793",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-102821",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-30T19:34:47.748081Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-29T19:17:23.993",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Eugeny/russh/commit/a282af361ac99bc76b80876d1aae128e89dbf66b"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Eugeny/russh/releases/tag/v0.63.2"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Eugeny/russh/security/advisories/GHSA-35g8-35p8-c8fw"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/Eugeny/russh/security/advisories/GHSA-35g8-35p8-c8fw"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-400"
        },
        {
          "lang": "en",
          "value": "CWE-770"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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