CVE-2022-39386
fastify-websocket vulnerable to uncaught exception via crash on malformed packet
@fastify/websocket provides WebSocket support for Fastify. Any application using @fastify/websocket could crash if a specific, malformed packet is sent. All versions of fastify-websocket are also impacted. That module is deprecated, so it will not be patched. This has been patched in version 7.1.1 (fastify v4) and version 5.0.1 (fastify v3). There are currently no known workarounds. However, it should be possible to attach the error handler manually. The recommended path is upgrading to the patched versions.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
fastify-websocket vulnerable to uncaught exception via crash on malformed packet
@fastify/websocket provides WebSocket support for Fastify. Any application using @fastify/websocket could crash if a specific, malformed packet is sent. All versions of fastify-websocket are also impacted. That module is deprecated, so it will not be patched. This has been patched in version 7.1.1 (fastify v4) and version 5.0.1 (fastify v3). There are currently no known workarounds. However, it should be possible to attach the error handler manually. The recommended path is upgrading to the patched versions.
- Record
CVE-2022-39386- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-248
- Updated
- 2026-11-02
EUVDEUVD-2022-7228
@fastify/websocket provides WebSocket support for Fastify. Any application using @fastify/websocket could crash if a specific, malformed packet is sent. All versions of fastify-websocket are also impacted. That module is deprecated, so it will not be patched. This has been patched in version 7.1.1 (fastify v4) and version 5.0.1 (fastify v3). There are currently no known workarounds. However, it should be possible to attach the error handler manually. The recommended path is upgrading to the patched versions.
- Record
EUVD-2022-7228- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-4pcg-wr6c-h9cq
fastify/websocket vulnerable to uncaught exception via crash on malformed packet
Impact
Any application using @fastify/websocket could crash if a specific, malformed packet is sent.
All versions of fastify-websocket are also impacted. That module is deprecated, so it will not be patched.
Patches
This has been patched in v7.1.1 (fastify v4) and v5.0.1 (fastify v3).
Workarounds
No known workaround is available. However, it should be possible to attach the error handler manually. The recommended path is upgrading to the patched versions.
Credits
marcolanaro for finding and patching this vulnerability
For more information
If you have any questions or comments about this advisory:
- Open an issue in @fastify/websocket
- Email us at [email protected]
- Record
GHSA-4pcg-wr6c-h9cq- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-248
- Updated
- 2026-11-02
NVD
@fastify/websocket provides WebSocket support for Fastify. Any application using @fastify/websocket could crash if a specific, malformed packet is sent. All versions of fastify-websocket are also impacted. That module is deprecated, so it will not be patched. This has been patched in version 7.1.1 (fastify v4) and version 5.0.1 (fastify v3). There are currently no known workarounds. However, it should be possible to attach the error handler manually. The recommended path is upgrading to the patched versions.
- Record
CVE-2022-39386- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-248
- Updated
- 2026-11-02
OSV
fastify-websocket vulnerable to uncaught exception via crash on malformed packet
@fastify/websocket provides WebSocket support for Fastify. Any application using @fastify/websocket could crash if a specific, malformed packet is sent. All versions of fastify-websocket are also impacted. That module is deprecated, so it will not be patched. This has been patched in version 7.1.1 (fastify v4) and version 5.0.1 (fastify v3). There are currently no known workarounds. However, it should be possible to attach the error handler manually. The recommended path is upgrading to the patched versions.
- Record
CVE-2022-39386- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-248
- Updated
- 2026-11-02
OSVGHSA-4pcg-wr6c-h9cq
fastify/websocket vulnerable to uncaught exception via crash on malformed packet
Impact
Any application using @fastify/websocket could crash if a specific, malformed packet is sent.
All versions of fastify-websocket are also impacted. That module is deprecated, so it will not be patched.
Patches
This has been patched in v7.1.1 (fastify v4) and v5.0.1 (fastify v3).
Workarounds
No known workaround is available. However, it should be possible to attach the error handler manually. The recommended path is upgrading to the patched versions.
Credits
marcolanaro for finding and patching this vulnerability
For more information
If you have any questions or comments about this advisory:
- Open an issue in @fastify/websocket
- Email us at [email protected]
- Record
GHSA-4pcg-wr6c-h9cq- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-248
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
@fastify/websocketnpm |
6.0.0 up to 7.1.1 | 7.1.1 |
fastify-websocketnpm |
through 4.3.0 | None known |
@fastify/websocketnpm |
5.0.0 up to 5.0.1 | 5.0.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2022-39386 is a high vulnerability (CVSS 7.5) in Fastify Fastify-websocket, published November 7, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.86%, the 58th percentile. Fixed in @fastify/websocket 7.1.1.
References
github.com/fastify/fastify-websocket/security/advisories/GHSA-4pcg-wr6c-h9cq
nvd.nist.gov/vuln/detail/CVE-2022-39386