Socket.io - Improper type validation in attachment parsing
Priority MEDIUM 52CWE-89Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- SQL injection
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-89.
Summary
Due to improper type validation in attachment parsing the Socket.io js library, it is possible to overwrite the _placeholder object which allows an attacker to place references to functions at arbitrary places in the resulting query object.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01431 73rd percentileScored 2026-11-07
Fix Fixed Socket.io-Parser (Socket.io): 4.2.1socket.io-parser (npm): 4.0.5, 4.2.1, 3.3.3 +1
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| @socket.io | Socket.io-Parser | 4.x to before 4.2.1 | 4.2.1 | Patch available | CNA |
| — | socket.io-parser (npm) | 4.0.0 to before 4.0.5 | 4.0.5 | Patch available | GHSA-qm95-pgcg-qqfq |
| — | socket.io-parser (npm) | 4.1.0 to before 4.2.1 | 4.2.1 | Patch available | GHSA-qm95-pgcg-qqfq |
| — | socket.io-parser (npm) | before 3.3.3 | 3.3.3 | Patch available | GHSA-qm95-pgcg-qqfq |
| — | socket.io-parser (npm) | 3.4.0 to before 3.4.2 | 3.4.2 | Patch available | GHSA-qm95-pgcg-qqfq |
- Socket.io-Parser Vendor@socket.io Affected 4.x to before 4.2.1 Fixed in 4.2.1 Patch available CNA
- socket.io-parser (npm) Vendor— Affected 4.0.0 to before 4.0.5 Fixed in 4.0.5 Patch available GHSA-qm95-pgcg-qqfq
- socket.io-parser (npm) Vendor— Affected 4.1.0 to before 4.2.1 Fixed in 4.2.1 Patch available GHSA-qm95-pgcg-qqfq
- socket.io-parser (npm) Vendor— Affected before 3.3.3 Fixed in 3.3.3 Patch available GHSA-qm95-pgcg-qqfq
- socket.io-parser (npm) Vendor— Affected 3.4.0 to before 3.4.2 Fixed in 3.4.2 Patch available GHSA-qm95-pgcg-qqfq
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:socket:socket.io-parser:*:*:*:*:*:node.js:*:* | before 3.3.3; 3.4.0 to before 3.4.2; 4.0.0 to before 4.0.5; 4.1.0 to before 4.2.1 | Vulnerable | socketio |
- cpe:2.3:a:socket:socket.io-parser:*:*:*:*:*:node.js:*:* Versions before 3.3.3; 3.4.0 to before 3.4.2; 4.0.0 to before 4.0.5; 4.1.0 to before 4.2.1 Vulnerable ·socketio
Remediation
- Fix · CNA Socket.io-Parser (Socket.io) Fixed in 4.2.1
- Fix · GHSA-qm95-pgcg-qqfq socket.io-parser (npm) Fixed in 4.0.5 Advisory →
- Fix · GHSA-qm95-pgcg-qqfq socket.io-parser (npm) Fixed in 4.2.1 Advisory →
- Fix · GHSA-qm95-pgcg-qqfq socket.io-parser (npm) Fixed in 3.3.3 Advisory →
- Fix · GHSA-qm95-pgcg-qqfq socket.io-parser (npm) Fixed in 3.4.2 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2022-2421
- 2026-10-03 Alias added: GHSA-qm95-pgcg-qqfq
References
Advisory 3
Other 7
- https://github.com/socketio/socket.io-parser/commit/04d23cecafe1b859fb03e0cbf6ba3b74dff56d14
- https://github.com/socketio/socket.io-parser/commit/b559f050ee02bd90bd853b9823f8de7fa94a80d4
- https://github.com/socketio/socket.io-parser/commit/b5d0cb7dc56a0601a09b056beaeeb0e43b160050
- https://github.com/socketio/socket.io-parser/commit/fb21e422fc193b34347395a33e0f625bebc09983
- https://csirt.divd.nl/cases/DIVD-2022-00045
- https://csirt.divd.nl/cves/CVE-2022-2421
- https://github.com/socketio/socket.io-parser
More @socket.io vulnerabilities
- TI-2026-65444 Socket.IO: Prototype Pollution via Unsafe Client Session Lookup CVSS 3.1HIGH 7.5
Sources
- CVE-2022-2421 · CVE Program
- CVE-2022-2421 · NVD
- FIRST EPSS
- GHSA-qm95-pgcg-qqfq · GitHub Advisory Database · CC BY 4.0
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