# CVE-2026-109841: node-undici: undici is an HTTP client library for Node.js

CVE-2026-109841 is fixed in 11 products on 1 platform, first by DEBIAN-CVE-2026-109841, released November 1, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-109841
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0025
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 15, 2026

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | node-undici Debian 14 | 8.12.2+dfsg+~cs3.2.3-1 | [DEBIAN-CVE-2026-109841](https://patchblox.com/security/data/fix/linux/debian-cve-2026-109841.md) | Nov 1, 2026 |
| Linux | nodejs24 amzn 2023 | 1:24.22.1-1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |
| Linux | nodejs24-debuginfo amzn 2023 | 1:24.22.1-1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |
| Linux | nodejs24-debugsource amzn 2023 | 1:24.22.1-1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |
| Linux | nodejs24-devel amzn 2023 | 1:24.22.1-1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |
| Linux | nodejs24-docs amzn 2023 | 1:24.22.1-1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |
| Linux | nodejs24-full-i18n amzn 2023 | 1:24.22.1-1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |
| Linux | nodejs24-libs amzn 2023 | 1:24.22.1-1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |
| Linux | nodejs24-libs-debuginfo amzn 2023 | 1:24.22.1-1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |
| Linux | nodejs24-npm amzn 2023 | 1:11.19.1-1.24.22.1.1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |
| Linux | v8-13.6-devel amzn 2023 | 3:13.6.233.17-1.24.22.1.1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |

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Data as of 2026-11-09T19:38:12Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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