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

Vulnerability from cvelistv5 – Published: 2026-10-15 18:22 – Updated: 2026-10-16 20:04
VLAI
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 108 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
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)
guessed Create a notification for this product.
Credits
Kushalkhemka mayank-jangid-moon opensec-intelligence mcollina UlisesGascon skigeek16 KhafraDev
Show details on NVD website
To clipboard 

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