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CVE

CVE-2026-2229

ImpactThe undici WebSocket client is vulnerable to a denial-of-service attack due to improper validation of the server_max_window_bits parameter in the permessage-deflate extension.
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CVE

CVE-2026-2229

ImpactThe undici WebSocket client is vulnerable to a denial-of-service attack due to improper validation of the server_max_window_bits parameter in the permessage-deflate extension.

ImpactThe undici WebSocket client is vulnerable to a denial-of-service attack due to improper validation of the servermaxwindowbits parameter in the permessage-deflate extension. When a WebSocket client connects to a server, it automatically advertises support for permessage-deflate compression. A malicious server can respond with an out-of-range servermaxwindowbits value (outside zlib's valid range of 8-15). When the server subsequently sends a compressed frame, the client attempts to create a zlib InflateRaw instance with the invalid windowBits value, causing a synchronous RangeError exception that is not caught, resulting in immediate process termination.

The vulnerability exists because:

  •  The isValidClientWindowBits() function only validates that the value contains ASCII digits, not that it falls within the valid range 8-15
  •  The createInflateRaw() call is not wrapped in a try-catch block
  •  The resulting exception propagates up through the call stack and crashes the Node.js process

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
7.5
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
C
H
U
0
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
C
H
U
-

Related Resources

No items found.

References

https://cna.openjsf.org/security-advisories.html, https://github.com/nodejs/undici/security/advisories/GHSA-v9p9-hfj2-hcw8, https://hackerone.com/reports/3487486, https://datatracker.ietf.org/doc/html/rfc7692, https://nodejs.org/api/zlib.html#class-zlibinflateraw

Severity

7.5

CVSS Score
0
10

Basic Information

Ecosystem
Base CVSS
7.5
EPSS Probability
0.00203%
EPSS Percentile
0.42203%
Introduced Version
1cfe0949053aac6267f11b919cee9315a27f1fd6,0
Fix Available
07a39067a0485c1953196f500d945fe09378a176,1:24.14.1-2.module+el8.10.0+24190+49a46c75,0:2021.06-6.module+el8.10.0+24190+49a46c75,3:13.6.233.17-1.24.14.1.2.module+el8.10.0+24190+49a46c75,0:3.0.3-1.module+el8.10.0+24190+49a46c75,1:11.11.0-1.24.14.1.2.module+el8.10.0+24190+49a46c75,0:3.0.1-1.module+el8.10.0+24148+847b6786,0:2021.06-6.module+el8.10.0+24148+847b6786,1:22.22.2-1.module+el8.10.0+24148+847b6786,1:10.9.7-1.22.22.2.1.module+el8.10.0+24148+847b6786,3:12.4.254.21-1.22.22.2.1.module+el8.10.0+24148+847b6786,1:24.14.1-2.module+el9.7.0+24166+51c9666b,0:3.0.3-3.module+el9.7.0+24166+51c9666b,0:2021.06-6.module+el9.7.0+24166+51c9666b,1:11.11.0-1.24.14.1.2.module+el9.7.0+24166+51c9666b,3:13.6.233.17-1.24.14.1.2.module+el9.7.0+24166+51c9666b,1:22.22.2-1.module+el9.7.0+24157+8ddb2461,0:3.0.1-1.module+el9.7.0+24157+8ddb2461,0:2021.06-6.module+el9.7.0+24157+8ddb2461,1:10.9.7-1.22.22.2.1.module+el9.7.0+24157+8ddb2461,3:12.4.254.21-1.22.22.2.1.module+el9.7.0+24157+8ddb2461,1:24.14.1-2.module+el9.7.0+90866+5a953a4c,0:3.0.3-3.module+el9.7.0+90866+5a953a4c,0:2021.06-6.module+el9.7.0+90866+5a953a4c,1:11.11.0-1.24.14.1.2.module+el9.7.0+90866+5a953a4c,3:13.6.233.17-1.24.14.1.2.module+el9.7.0+90866+5a953a4c,1:22.22.2-1.module+el9.7.0+90867+2ede48fe,0:3.0.1-1.module+el9.7.0+90867+2ede48fe,0:2021.06-6.module+el9.7.0+90867+2ede48fe,1:10.9.7-1.22.22.2.1.module+el9.7.0+90867+2ede48fe,3:12.4.254.21-1.22.22.2.1.module+el9.7.0+90867+2ede48fe,1:24.14.1-2.module+el8.10.0+90873+35652ecc,0:3.0.3-1.module+el8.10.0+90873+35652ecc,0:2021.06-6.module+el8.10.0+90873+35652ecc,1:11.11.0-1.24.14.1.2.module+el8.10.0+90873+35652ecc,3:13.6.233.17-1.24.14.1.2.module+el8.10.0+90873+35652ecc,1:22.22.2-1.module+el8.10.0+90865+d647ef3a,0:3.0.1-1.module+el8.10.0+90865+d647ef3a,0:2021.06-4.module+el8.10.0+90865+d647ef3a,1:10.9.7-1.22.22.2.1.module+el8.10.0+90865+d647ef3a,3:12.4.254.21-1.22.22.2.1.module+el8.10.0+90865+d647ef3a,1:20.20.1-1.amzn2023.0.3,3:11.3.244.8-1.20.20.1.1.amzn2023.0.3,1:10.8.2-1.20.20.1.1.amzn2023.0.3,1:22.22.1-1.amzn2023.0.2,3:12.4.254.21-1.22.22.1.1.amzn2023.0.2,1:10.9.4-1.22.22.1.1.amzn2023.0.2,1:24.14.0-1.amzn2023.0.2,3:13.6.233.17-1.24.14.0.1.amzn2023.0.2,1:11.9.0-1.24.14.0.1.amzn2023.0.2,4.110.1-r2,2.11.0-r17,8.17.10-r13,8.18.8-r11,8.19.13-r4,9.0.8-r14,9.1.10-r7,9.2.7-r0,9.3.2-r0,0.8.4-r3,7.6.0-r4,43.84.0-r1

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