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.
References
| Link | Resource |
|---|---|
| https://cna.openjsf.org/security-advisories.html | Vendor Advisory |
| https://github.com/nodejs/undici/security/advisories/GHSA-f72v-6w45-q472 | Mitigation Vendor Advisory |
Configurations
Configuration 1 (hide)
|
History
19 Oct 2026, 20:45
| Type | Values Removed | Values Added |
|---|---|---|
| CPE | cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:* | |
| First Time |
Nodejs
Nodejs undici |
|
| References | () https://cna.openjsf.org/security-advisories.html - Vendor Advisory | |
| References | () https://github.com/nodejs/undici/security/advisories/GHSA-f72v-6w45-q472 - Mitigation, Vendor Advisory |
15 Oct 2026, 19:17
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-10-15 19:17
Updated : 2026-10-19 20:45
NVD link : CVE-2026-109841
Mitre link : CVE-2026-109841
CVE.ORG link : CVE-2026-109841
JSON object : View
Products Affected
nodejs
- undici
CWE
CWE-178
Improper Handling of Case Sensitivity
