CVE-2022-21676

mediumpriority · track · 31EPSS 0.028 · 86 %ileEUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
2.76% (86th) EPSS
CVSS 5 · medium
Is it mine?
9 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · nvd · osv

EPSS · scored 2026-10-28

Engine.IO is the implementation of transport-based cross-browser/cross-device bi-directional communication layer for Socket.IO. A specially crafted HTTP request can trigger an uncaught exception on the Engine.IO server, thus killing the Node.js process. This impacts all the users of the `engine.io` package starting from version `4.0.0`, including those who uses depending packages like `socket.io`. Versions prior to `4.0.0` are not impacted. A fix has been released for each major branch, namely `4.1.2` for the `4.x.x` branch, `5.2.1` for the `5.x.x` branch, and `6.1.1` for the `6.x.x` branch. There is no known workaround except upgrading to a safe version.

01

cvss

Technical severity, 0–10. One row per scoring source.

7.5
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5–7.5

v2.05mediumAV:N/AC:L/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 10 · impact 2.9
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · ENISA EU
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · security-advisories@github.comexploitability 3.9 · impact 3.6
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · OSV
v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

04

affected products (9)

Products and version ranges known to be affected.

05

advisories (1)

Vendor and ecosystem advisories describing this.

  • GHSA-273r-mgr4-v34fUncaught Exception in engine.io2022-01-13ghsa · osvUS

    ### Impact A specially crafted HTTP request can trigger an uncaught exception on the Engine.IO server, thus killing the Node.js process. > RangeError: Invalid WebSocket frame: RSV2 and RSV3 must be clear > at Receiver.getInfo (/.../node_modules/ws/lib/receiver.js:176:14) > at Receiver.startLoop (/.../node_modules/ws/lib/receiver.js:136:22) > at Receiver._write (/.../node_modules/ws/lib/receiver.js:83:10) > at writeOrBuffer (internal/streams/writable.js:358:12) This impacts all the users of the [`engine.io`](https://www.npmjs.com/package/engine.io) package starting from version `4.0.0`, including those who uses depending packages like [`socket.io`](https://www.npmjs.com/package/socket.io). ### Patches A fix has been released for each major branch: | Version range | Fixed version | | --- | --- | | `engine.io@4.x.x` | `4.1.2` | | `engine.io@5.x.x` | `5.2.1` | | `engine.io@6.x.x` | `6.1.1` | Previous versions (`< 4.0.0`) are not impacted. For `socket.io` users: | Version range | `engine.io` version | Needs minor update? | | --- | --- | --- | | `socket.io@4.4.x` | `~6.1.0` | - | `socket.io@4.3.x` | `~6.0.0` | Please upgrade to `socket.io@4.4.x` | `socket.io@4.2.x` | `~5.2.0` | - | `socket.io@4.1.x` | `~5.1.1` | Please upgrade to `socket.io@4.4.x` | `socket.io@4.0.x` | `~5.0.0` | Please upgrade to `socket.io@4.4.x` | `socket.io@3.1.x` | `~4.1.0` | - | `socket.io@3.0.x` | `~4.0.0` | Please upgrade to `socket.io@3.1.x` or `socket.io@4.4.x` (see [here](https://socket.io/docs/v4/migrating-from-3-x-to-4-0/)) In most cases, running `npm audit fix` should be sufficient. You can also use `npm update engine.io --depth=9999`. ### Workarounds There is no known workaround except upgrading to a safe version. ### For more information If you have any questions or comments about this advisory: * Open an issue in [`engine.io`](https://github.com/socketio/engine.io) Thanks to Marcus Wejderot from Mevisio for the responsible disclosure.

06

also known as (3)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

published 2022-01-12modified 2026-06-17
09

references (25)

External citations — patches, advisories, analysis.

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