FKIE_CVE-2026-45185

Vulnerability from fkie_nvd - Published: 2026-05-12 20:16 - Updated: 2026-05-28 18:46
Severity
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing path. It is triggered when a client sends a TLS close_notify mid-body during a CHUNKING transfer, followed by a final cleartext byte on the same TCP connection. This can lead to heap corruption. An unauthenticated network attacker exploiting this vulnerability could execute arbitrary code.
References
cve@mitre.orghttps://code.exim.org/exim/wiki/wiki/EximSecurityVendor Advisory
cve@mitre.orghttps://exim.orgProduct
cve@mitre.orghttps://exim.org/static/doc/security/CVE-2026-45185.txtBroken Link
cve@mitre.orghttps://exim.org/static/doc/security/EXIM-Security-2026-05-01.1/Release Notes
cve@mitre.orghttps://news.ycombinator.com/item?id=48111748Issue Tracking
cve@mitre.orghttps://www.openwall.com/lists/oss-security/2026/05/12/4Mailing List, Third Party Advisory
cve@mitre.orghttps://xbow.com/blog/dead-letter-cve-2026-45185-xbow-found-rce-eximThird Party Advisory
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2026/05/12/25Mailing List, Third Party Advisory
Impacted products
Vendor Product Version
exim exim *
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:exim:exim:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "B6F6BADD-C865-40D6-BE0A-BC7389F40FFA",
              "versionEndExcluding": "4.99.3",
              "versionStartIncluding": "4.97",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing path. It is triggered when a client sends a TLS close_notify mid-body during a CHUNKING transfer, followed by a final cleartext byte on the same TCP connection. This can lead to heap corruption. An unauthenticated network attacker exploiting this vulnerability could execute arbitrary code."
    }
  ],
  "id": "CVE-2026-45185",
  "lastModified": "2026-05-28T18:46:27.410",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "cve@mitre.org",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-05-12T20:16:46.137",
  "references": [
    {
      "source": "cve@mitre.org",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://code.exim.org/exim/wiki/wiki/EximSecurity"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Product"
      ],
      "url": "https://exim.org"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Broken Link"
      ],
      "url": "https://exim.org/static/doc/security/CVE-2026-45185.txt"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Release Notes"
      ],
      "url": "https://exim.org/static/doc/security/EXIM-Security-2026-05-01.1/"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Issue Tracking"
      ],
      "url": "https://news.ycombinator.com/item?id=48111748"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ],
      "url": "https://www.openwall.com/lists/oss-security/2026/05/12/4"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://xbow.com/blog/dead-letter-cve-2026-45185-xbow-found-rce-exim"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ],
      "url": "http://www.openwall.com/lists/oss-security/2026/05/12/25"
    }
  ],
  "sourceIdentifier": "cve@mitre.org",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ],
      "source": "cve@mitre.org",
      "type": "Secondary"
    }
  ]
}


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