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GHSA-9XWW-74XV-GJFP

Vulnerability from github – Published: 2026-09-15 19:54 – Updated: 2026-09-15 19:54
VLAI
Summary
Http4s: DigestAuth allows replay of captured requests
Details

The DigestAuth replay defence stores lastNc + 1 rather than the nonce-count (nc) value it just accepted. When a legitimate client sends non-contiguous nc values (parallel or retried requests, as browsers do), the server's counter lags behind the highest nc seen, and a captured Authorization header can be replayed multiple times.

Impact

A passive observer can turn one captured Digest-authenticated request into several replayed authenticated (state-changing) requests, defeating the core replay protection Digest provides over Basic.

Preconditions

  • Application uses DigestAuth.
  • Attacker can passively observe at least one legitimate digest request.
  • Legitimate client emits an nc more than one greater than the last, for instance from a parallel or retried request.

Workarounds

  • Deploy over TLS so requests cannot be captured.
Severity
5.9 (Medium)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Show details on source website
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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 0.23.34"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "org.http4s:http4s-ember-core_2.12"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.23.35"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 0.23.34"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "org.http4s:http4s-ember-core_2.13"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.23.35"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 0.23.34"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "org.http4s:http4s-ember-core_3"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.23.35"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.0.0-M46"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "org.http4s:http4s-ember-core_2.13"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.0.0-M1"
            },
            {
              "fixed": "1.0.0-M47"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.0.0-M46"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "org.http4s:http4s-ember-core_3"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.0.0-M1"
            },
            {
              "fixed": "1.0.0-M47"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-69206"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-294"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-15T19:54:32Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "The `DigestAuth` replay defence stores `lastNc + 1` rather than the nonce-count (`nc`) value it just accepted. When a legitimate client sends non-contiguous `nc` values (parallel or retried requests, as browsers do), the server\u0027s counter lags behind the highest `nc` seen, and a captured `Authorization` header can be replayed multiple times.\n\n## Impact\n\nA passive observer can turn one captured Digest-authenticated request into several replayed authenticated (state-changing) requests, defeating the core\nreplay protection Digest provides over Basic.\n\n## Preconditions\n\n- Application uses `DigestAuth`.\n- Attacker can passively observe at least one legitimate digest request.\n- Legitimate client emits an `nc` more than one greater than the last, for instance from a parallel or retried request.\n\n## Workarounds\n\n- Deploy over TLS so requests cannot be captured.",
  "id": "GHSA-9xww-74xv-gjfp",
  "modified": "2026-09-15T19:54:32Z",
  "published": "2026-09-15T19:54:32Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/http4s/http4s/security/advisories/GHSA-9xww-74xv-gjfp"
    },
    {
      "type": "WEB",
      "url": "https://github.com/http4s/http4s/commit/7f065101c45f3d86bc105e8fc6323c2c4a11471f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/http4s/http4s"
    },
    {
      "type": "WEB",
      "url": "https://github.com/http4s/http4s/releases/tag/v0.23.35"
    },
    {
      "type": "WEB",
      "url": "https://github.com/http4s/http4s/releases/tag/v1.0.0-M47"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Http4s: DigestAuth allows replay of captured requests"
}



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