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CVE

CVE-2026-1526

The undici WebSocket client is vulnerable to a denial-of-service attack via unbounded memory consumption during permessage-deflate decompression.
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CVE

CVE-2026-1526

The undici WebSocket client is vulnerable to a denial-of-service attack via unbounded memory consumption during permessage-deflate decompression.

The undici WebSocket client is vulnerable to a denial-of-service attack via unbounded memory consumption during permessage-deflate decompression. When a WebSocket connection negotiates the permessage-deflate extension, the client decompresses incoming compressed frames without enforcing any limit on the decompressed data size. A malicious WebSocket server can send a small compressed frame (a "decompression bomb") that expands to an extremely large size in memory, causing the Node.js process to exhaust available memory and crash or become unresponsive.

The vulnerability exists in the PerMessageDeflate.decompress() method, which accumulates all decompressed chunks in memory and concatenates them into a single Buffer without checking whether the total size exceeds a safe threshold.

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-vrm6-8vpv-qv8q, https://hackerone.com/reports/3481206, https://datatracker.ietf.org/doc/html/rfc7692

Severity

7.5

CVSS Score
0
10

Basic Information

Ecosystem
Base CVSS
7.5
EPSS Probability
0.0002%
EPSS Percentile
0.05771%
Introduced Version
1cfe0949053aac6267f11b919cee9315a27f1fd6,0
Fix Available
07a39067a0485c1953196f500d945fe09378a176,1:24.14.1-2.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+8ddb2461,0:2021.06-6.module+el9.7.0+24157+8ddb2461,1:10.9.7-1.22.22.2.1.module+el9.7.0+24157+8ddb2461,0:3.0.1-1.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+el8.10.0+24190+49a46c75,0:2021.06-6.module+el8.10.0+24190+49a46c75,1:11.11.0-1.24.14.1.2.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+49a46c75,1:22.22.2-1.module+el8.10.0+24148+847b6786,0:3.0.1-1.module+el8.10.0+24148+847b6786,0:2021.06-6.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+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,1:24.14.1-2.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,1:20.20.1-1.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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