Vulnerability-Lookup

GHSA-JR45-8VMC-QM54

Vulnerability from github – Published: 2026-08-03 19:32 – Updated: 2026-08-03 19:32

Summary

undici vulnerable to cross-user information disclosure via whitespace around equals in Cache-Control directives

Details

Impact

Undici's cache interceptor mishandles optional whitespace (OWS) placed around the = of a qualified no-cache or private Cache-Control directive, such as no-cache ="authorization" (OWS before =) or no-cache= "authorization" (OWS after =). The parser either drops the directive entirely or stores a field name with literal quote characters, so the downstream cache decisions do not recognize the qualification and the response is stored.

In shared-cache mode, this allows a response containing one user's authenticated data to be served from cache to a subsequent caller, including an unauthenticated caller, when both requests resolve to the same cache key. The impact class is identical to CVE-2026-9678 (GHSA-pr7r-676h-xcf6); this advisory covers the whitespace-around-= bypass that the earlier fix did not normalize.

Affected applications are those that explicitly enable the cache interceptor (interceptors.cache()) in shared mode, forward Authorization headers upstream, and receive cacheable responses with qualified private or no-cache directives whose field-name list is padded with OWS around the =.

Patches

Upgrade to undici v7.29.0 or v8.9.0.

Workarounds

If upgrade is not immediately possible, disable shared-cache mode for traffic that includes Authorization headers, avoid caching responses to authenticated requests, or add Vary: Authorization upstream.

Severity

5.9 (Medium)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

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JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "undici"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "7.0.0"
            },
            {
              "fixed": "7.29.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "undici"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.0.0"
            },
            {
              "fixed": "8.9.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-14643"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-436",
      "CWE-524"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-08-03T19:32:12Z",
    "nvd_published_at": "2026-07-29T22:16:52Z",
    "severity": "MODERATE"
  },
  "details": "## Impact\n\nUndici\u0027s cache interceptor mishandles optional whitespace (OWS) placed around the `=` of a qualified `no-cache` or `private` Cache-Control directive, such as `no-cache =\"authorization\"` (OWS before `=`) or `no-cache= \"authorization\"` (OWS after `=`). The parser either drops the directive entirely or stores a field name with literal quote characters, so the downstream cache decisions do not recognize the qualification and the response is stored.\n\nIn shared-cache mode, this allows a response containing one user\u0027s authenticated data to be served from cache to a subsequent caller, including an unauthenticated caller, when both requests resolve to the same cache key. The impact class is identical to CVE-2026-9678 (GHSA-pr7r-676h-xcf6); this advisory covers the whitespace-around-`=` bypass that the earlier fix did not normalize.\n\nAffected applications are those that explicitly enable the cache interceptor (`interceptors.cache()`) in shared mode, forward `Authorization` headers upstream, and receive cacheable responses with qualified `private` or `no-cache` directives whose field-name list is padded with OWS around the `=`.\n\n## Patches\n\nUpgrade to undici v7.29.0 or v8.9.0.\n\n## Workarounds\n\nIf upgrade is not immediately possible, disable shared-cache mode for traffic that includes `Authorization` headers, avoid caching responses to authenticated requests, or add `Vary: Authorization` upstream.",
  "id": "GHSA-jr45-8vmc-qm54",
  "modified": "2026-08-03T19:32:12Z",
  "published": "2026-08-03T19:32:12Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/nodejs/undici/security/advisories/GHSA-jr45-8vmc-qm54"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-14643"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nodejs/undici/commit/85a240551c9feb8b8a0ecc56c84b2b3015add8a9"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nodejs/undici/commit/cb105d7c79069150982fa11acada0dd94a60dbbc"
    },
    {
      "type": "WEB",
      "url": "https://cna.openjsf.org/security-advisories.html"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/nodejs/undici"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nodejs/undici/releases/tag/v7.29.0"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nodejs/undici/releases/tag/v8.9.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "undici vulnerable to cross-user information disclosure via whitespace around equals in Cache-Control directives"
}

CVE-2026-14643 (GCVE-0-2026-14643)

Vulnerability from cvelistv5 – Published: 2026-07-29 21:08 – Updated: 2026-07-30 15:18

Title

undici vulnerable to cross-user information disclosure via whitespace around equals in Cache-Control directives

Summary

undici's cache interceptor mishandles optional whitespace placed around the equals sign of a qualified no-cache or private Cache-Control directive. In undici from 7.0.0 up to before 7.29.0 and from 8.0.0 up to before 8.9.0, the parser either drops the directive or stores a field name with literal quote characters, so the cache decision fails to recognize the qualification and the response is stored. In shared-cache mode, this lets a response containing one user's authenticated data be served from cache to a later caller, including an unauthenticated one, when both requests resolve to the same cache key. It affects applications that enable the cache interceptor in shared mode, forward Authorization headers upstream, and receive cacheable responses with qualified directives padded with whitespace around the equals sign. This is the whitespace-around-equals variant that the fix for CVE-2026-9678 did not normalize, and it is fixed in undici 7.29.0 and 8.9.0.

Severity

5.9 (Medium)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-436 - Interpretation Conflict
CWE-524 - Use of Cache Containing Sensitive Information

Assigner

openjs

References

2 references

URL	Tags
https://github.com/nodejs/undici/security/advisor…
https://cna.openjsf.org/security-advisories.html

Impacted products

1 product

Vendor	Product	Version
undici	undici	Affected: 7.0.0 , < 7.29.0 (semver) Unaffected: 7.29.0 (semver) Affected: 8.0.0 , < 8.9.0 (semver) Unaffected: 8.9.0 (semver)

Credits

rampage0010 mcollina UlisesGascon

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JSON

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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

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