Vulnerability · Published Mar 30, 2026 · Assigned by hackerone
CVE-2026-21717
Medium 5.9
In plain English
A medium-severity security flaw in node from nodejs. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official description
A flaw in V8's string hashing mechanism causes integer-like strings to be hashed to their numeric value, making hash collisions trivially predictable. By crafting a request that causes many such collisions in V8's internal string table, an attacker can significantly degrade performance of the Node.js process. The most common trigger is any endpoint that calls `JSON.parse()` on attacker-controlled input, as JSON parsing automatically internalizes short strings into the affected hash table. This vulnerability affects **20.x, 22.x, 24.x, and 25.x**.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | nodejs | 1:24.14.1-2.module_el8.10.0+4160+4819ac42 | ALSA-2026:7670 |
| AlmaLinux:9 | nodejs | 1:24.14.1-2.module_el9.7.0+222+ef1c61e1 | ALSA-2026:7350 |
| AlmaLinux:8 | nodejs-devel | 1:24.14.1-2.module_el8.10.0+4160+4819ac42 | ALSA-2026:7670 |
| AlmaLinux:9 | nodejs-devel | 1:24.14.1-2.module_el9.7.0+222+ef1c61e1 | ALSA-2026:7350 |
| AlmaLinux:8 | nodejs-docs | 1:24.14.1-2.module_el8.10.0+4160+4819ac42 | ALSA-2026:7670 |
| AlmaLinux:9 | nodejs-docs | 1:24.14.1-2.module_el9.7.0+222+ef1c61e1 | ALSA-2026:7350 |
| AlmaLinux:8 | nodejs-full-i18n | 1:24.14.1-2.module_el8.10.0+4160+4819ac42 | ALSA-2026:7670 |
| AlmaLinux:9 | nodejs-full-i18n | 1:24.14.1-2.module_el9.7.0+222+ef1c61e1 | ALSA-2026:7350 |
| AlmaLinux:8 | nodejs-libs | 1:24.14.1-2.module_el8.10.0+4160+4819ac42 | ALSA-2026:7670 |
| AlmaLinux:9 | nodejs-libs | 1:24.14.1-2.module_el9.7.0+222+ef1c61e1 | ALSA-2026:7350 |
| AlmaLinux:8 | nodejs-nodemon | 3.0.3-1.module_el8.10.0+4061+f8ceeab9 | ALSA-2026:7670 |
| AlmaLinux:9 | nodejs-nodemon | 3.0.3-3.module_el9.7.0+209+ecf6523e | ALSA-2026:7350 |
| AlmaLinux:8 | nodejs-packaging | 2021.06-6.module_el8.10.0+4086+70facd4a | ALSA-2026:7670 |
| AlmaLinux:9 | nodejs-packaging | 2021.06-6.module_el9.7.0+209+ecf6523e | ALSA-2026:7350 |
| AlmaLinux:8 | nodejs-packaging-bundler | 2021.06-6.module_el8.10.0+4086+70facd4a | ALSA-2026:7670 |
| AlmaLinux:9 | nodejs-packaging-bundler | 2021.06-6.module_el9.7.0+198+8bf605ba | ALSA-2026:7350 |
| AlmaLinux:10 | nodejs24-docs | 1:24.14.1-2.el10_1 | ALSA-2026:7675 |
| AlmaLinux:10 | nodejs24-npm | 1:11.11.0-1.24.14.1.2.el10_1 | ALSA-2026:7675 |
| AlmaLinux:8 | npm | 1:11.11.0-1.24.14.1.2.module_el8.10.0+4160+4819ac42 | ALSA-2026:7670 |
| AlmaLinux:9 | npm | 1:11.11.0-1.24.14.1.2.module_el9.7.0+222+ef1c61e1 | ALSA-2026:7350 |
| AlmaLinux:8 | v8-13.6-devel | 3:13.6.233.17-1.24.14.1.2.module_el8.10.0+4160+4819ac42 | ALSA-2026:7670 |
| AlmaLinux:9 | v8-13.6-devel | 3:13.6.233.17-1.24.14.1.2.module_el9.7.0+222+ef1c61e1 | ALSA-2026:7350 |
| Alpine:v3.21 | nodejs | 22.22.2-r0 | ALPINE-CVE-2026-21717 |
| Alpine:v3.22 | nodejs | 22.22.2-r0 | ALPINE-CVE-2026-21717 |
| Alpine:v3.23 | nodejs | 24.14.1-r0 | ALPINE-CVE-2026-21717 |
| Alpine:v3.24 | nodejs | 24.14.1-r0 | ALPINE-CVE-2026-21717 |
| Debian:12 | nodejs | no fix listed | DEBIAN-CVE-2026-21717 |
| Debian:13 | nodejs | 20.19.2+dfsg-1+deb13u2 | DSA-6183-1 |
| Debian:13 | nodejs | 20.19.2+dfsg-1+deb13u2 | DEBIAN-CVE-2026-21717 |
| Debian:14 | nodejs | 22.22.2+dfsg+~cs22.19.15-1 | DEBIAN-CVE-2026-21717 |
| Rocky Linux:8 | nodejs-nodemon | 0:3.0.3-1.module+el8.10.0+2084+ab509703 | RLSA-2026:7670 |
| Rocky Linux:9 | nodejs-nodemon | 0:3.0.3-3.module+el9.7.0+40025+0e0cf6b2 | RLSA-2026:7350 |
| Rocky Linux:8 | nodejs-packaging | 0:2021.06-6.module+el8.10.0+40048+6d99f608 | RLSA-2026:7670 |
| Rocky Linux:9 | nodejs-packaging | 0:2021.06-6.module+el9.7.0+40052+e32ea525 | RLSA-2026:7350 |
| Rocky Linux:10 | nodejs24 | 1:24.14.1-2.el10_1 | RLSA-2026:7675 |
| Ubuntu:24.04:LTS | nodejs | no fix listed | UBUNTU-CVE-2026-21717 |
| Ubuntu:25.10 | nodejs | no fix listed | UBUNTU-CVE-2026-21717 |
| Ubuntu:26.04:LTS | nodejs | no fix listed | UBUNTU-CVE-2026-21717 |
| Ubuntu:26.10 | nodejs | no fix listed | UBUNTU-CVE-2026-21717 |
Affected products (as reported)
Weakness: CWE-328 · Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H