CVE-2026-123609

Description

Rustls before 0.23.46 and 0.24.0-dev.1 before 0.24.0-dev.2 contains an information disclosure vulnerability where derived Debug formatting of client session values exposes secret key material. Custom ClientSessionStore implementations that log Tls12ClientSessionValue or Tls13ClientSessionValue can leak TLS 1.2 master secrets or TLS 1.3 resumption PSKs to log readers.

Overview

State: PUBLISHED
Assigner (CNA): VulnCheck
CVSS severity: MEDIUM
CVSS score: 4.1 / 10
CVSS vector: CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Effective score: 4.1 / 10 MEDIUM source: CNA overview
CWE(s): CWE-212
Reserved: 2026-11-06
Published: 2026-11-08 01:38 UTC
Last updated: 2026-11-08 01:38 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/123xxx/CVE-2026-123609.json

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID: EUVD-2026-119368

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Affected products (1)

Vendor	Product	Versions	Platforms
rustls	rustls	`0` (affected), `0.23.46` (unaffected), `0.24.0-dev.1` (affected), `0.24.0-dev.2` (unaffected)	—

Vendor references (2)

References embedded in the original CVE record by the assigning CNA.

GitHub Security Advisory (GHSA-c8m5-c952-6cm4) vendor-advisory
VulnCheck Advisory: Rustls before 0.23.46 and 0.24.0-dev.1 before 0.24.0-dev.2 Secret Exposure via Debug third-party-advisory

Web references (0)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

No web references attached yet.

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-123609.json.

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:cargo/rustls",
          "product": "rustls",
          "vendor": "rustls",
          "versions": [
            {
              "lessThan": "0.23.46",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "0.23.46",
              "versionType": "semver"
            },
            {
              "lessThan": "0.24.0-dev.2",
              "status": "affected",
              "version": "0.24.0-dev.1",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "0.24.0-dev.2",
              "versionType": "semver"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:rustls_project:rustls:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "0.23.46",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:rustls_project:rustls:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "0.24.0-dev.2",
                  "versionStartIncluding": "0.24.0-dev.1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "datePublic": "2026-10-14T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "Rustls before 0.23.46 and 0.24.0-dev.1 before 0.24.0-dev.2 contains an information disclosure vulnerability where derived Debug formatting of client session values exposes secret key material. Custom ClientSessionStore implementations that log Tls12ClientSessionValue or Tls13ClientSessionValue can leak TLS 1.2 master secrets or TLS 1.3 resumption PSKs to log readers."
        }
      ],
      "metrics": [
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            "attackComplexity": "HIGH",
            "attackRequirements": "PRESENT",
            "attackVector": "LOCAL",
            "baseScore": 4.1,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "HIGH",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "vectorString": "CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "NONE"
          },
          "format": "CVSS"
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        {
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            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "privilegesRequired": "HIGH",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N",
            "version": "3.1"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-212",
              "description": "Improper Removal of Sensitive Information Before Storage or Transfer",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-08T01:38:34.811Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "GitHub Security Advisory (GHSA-c8m5-c952-6cm4)",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://github.com/rustls/rustls/security/advisories/GHSA-c8m5-c952-6cm4"
        },
        {
          "name": "VulnCheck Advisory: Rustls before 0.23.46 and 0.24.0-dev.1 before 0.24.0-dev.2 Secret Exposure via Debug",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/rustls-before-0.23.46-and-0.24.0-dev.1-before-0.24.0-dev.2-secret-exposure-via-debug"
        }
      ],
      "title": "Rustls before 0.23.46 and 0.24.0-dev.1 before 0.24.0-dev.2 Secret Exposure via Debug",
      "x_generator": {
        "engine": "vulncheck-endgame"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-123609",
    "datePublished": "2026-11-08T01:38:34.811Z",
    "dateReserved": "2026-11-06T01:02:39.794Z",
    "dateUpdated": "2026-11-08T01:38:34.811Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}