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GHSA-F72V-6W45-Q472

Vulnerability from github – Published: 2026-10-23 22:12 – Updated: 2026-10-23 22:12

Summary

undici vulnerable to Subresource Integrity bypass via non-lowercase algorithm tokens

Details

Impact

undici's fetch() verifies Subresource Integrity (SRI) metadata by looking up the algorithm token in a lowercase-only set, but the SRI specification defines a valid token by its ASCII-lowercase form. A correct but non-lowercase token such as SHA256-... or Sha256-... is therefore treated as unknown and skipped. When no recognized algorithm remains, undici treats the integrity list as empty and accepts the response, so a server that returns a body different from the pinned digest passes the check.

An application that pins a response with a valid uppercase or mixed-case SRI token receives attacker-controlled bytes with no integrity error. The attacker needs only to control the response body, not the application's integrity metadata. The issue affects response integrity only. The regression was introduced in undici 7.15.0; releases 7.14.0 and earlier lowercase the token and are not affected.

Patches

Upgrade to 7.30.1 or 8.12.2. undici now normalizes the algorithm token to ASCII lowercase before validating it and before selecting the strongest algorithm, so case variants of SHA-256, SHA-384, and SHA-512 are verified correctly.

Workarounds

Use lowercase algorithm tokens (sha256, sha384, sha512) in integrity metadata.

Severity

5.9 (Medium)


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

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "undici"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "7.15.0"
            },
            {
              "fixed": "7.30.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "undici"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.0.0"
            },
            {
              "fixed": "8.12.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-109841"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-178"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-23T22:12:57Z",
    "nvd_published_at": "2026-10-15T19:17:21Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nundici\u0027s `fetch()` verifies Subresource Integrity (SRI) metadata by looking up the algorithm token in a lowercase-only set, but the SRI specification defines a valid token by its ASCII-lowercase form. A correct but non-lowercase token such as `SHA256-...` or `Sha256-...` is therefore treated as unknown and skipped. When no recognized algorithm remains, undici treats the integrity list as empty and accepts the response, so a server that returns a body different from the pinned digest passes the check.\n\nAn application that pins a response with a valid uppercase or mixed-case SRI token receives attacker-controlled bytes with no integrity error. The attacker needs only to control the response body, not the application\u0027s integrity metadata. The issue affects response integrity only. The regression was introduced in undici 7.15.0; releases 7.14.0 and earlier lowercase the token and are not affected.\n\n### Patches\n\nUpgrade to `7.30.1` or `8.12.2`. undici now normalizes the algorithm token to ASCII lowercase before validating it and before selecting the strongest algorithm, so case variants of SHA-256, SHA-384, and SHA-512 are verified correctly.\n\n### Workarounds\n\nUse lowercase algorithm tokens (`sha256`, `sha384`, `sha512`) in `integrity` metadata.",
  "id": "GHSA-f72v-6w45-q472",
  "modified": "2026-10-23T22:12:57Z",
  "published": "2026-10-23T22:12:57Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/nodejs/undici/security/advisories/GHSA-f72v-6w45-q472"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-109841"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nodejs/undici/commit/18bc8a1e09d15bc45815154a289dcf6fd5254d00"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nodejs/undici/commit/4f7ef6806e532ab9e29ccd6229b1b9d241e1b1f0"
    },
    {
      "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/v7.30.1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nodejs/undici/releases/tag/v8.12.2"
    }
  ],
  "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": "undici vulnerable to Subresource Integrity bypass via non-lowercase algorithm tokens"
}

CVE-2026-109841 (GCVE-0-2026-109841)

Vulnerability from cvelistv5 – Published: 2026-10-15 18:22 – Updated: 2026-10-16 20:04

Title

undici vulnerable to Subresource Integrity bypass via non-lowercase algorithm tokens

Summary

undici is an HTTP client library for Node.js. In versions 7.15.0 through 7.30.0 and 8.0.0 through 8.12.1, its fetch() implementation verifies Subresource Integrity metadata by matching the algorithm token against a lowercase-only set, even though the SRI specification defines the token by its ASCII-lowercase form, so a valid but non-lowercase token such as an uppercase or mixed-case SHA256 is treated as unknown and skipped. When no recognized algorithm remains, undici treats the integrity list as empty and accepts the response, so a server returning a body that does not match the pinned digest passes the check. An attacker who controls only the response body can therefore deliver attacker-controlled bytes to an application that pinned a valid uppercase or mixed-case SRI token, with no integrity error, affecting response integrity only. The issue is fixed in undici 7.30.1 and 8.12.2, which normalize the algorithm token to ASCII lowercase before validation, and users should upgrade to one of those versions or later. As a workaround, use lowercase algorithm tokens such as sha256, sha384, or sha512 in integrity metadata.

Severity

5.9 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-16 20:04 UTC

CWE

CWE-178 - Improper Handling of Case Sensitivity

Assigner

openjs CNA under the redhat root

CNA scorecard C 65/100 over 118 records in the last 180 days details

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: 7.15.0 , < 7.30.1 (semver) Unaffected: 7.30.1 (semver) Affected: 8.0.0 , < 8.12.2 (semver) Unaffected: 8.12.2 (semver)

Credits

Kushalkhemka mayank-jangid-moon opensec-intelligence mcollina UlisesGascon skigeek16 KhafraDev

Show details on NVD website

JSON

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Sightings

Author	Source	Type	Date	Other

Nomenclature

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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.

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