Application crash via unbounded WebSocket decompression
Published Apr 30, 2026 · Updated Apr 30, 2026
Resource exhaustion in Wireshark's WebSocket dissector in 4.6.0 through 4.6.4 and 4.4.0 through 4.4.14 allows attackers to crash the application. The websocket_uncompress function repeatedly enlarges a file-scope buffer while inflating permessage-deflate data, without limiting total decompressed output. Reaching the flaw requires a negotiated permessage-deflate WebSocket frame in live traffic or a crafted capture file that a user opens; the result is memory exhaustion and process termination.
Summary
What happened
Resource exhaustion in Wireshark's WebSocket dissector in 4.6.0 through 4.6.4 and 4.4.0 through 4.4.14 allows attackers to crash the application. The websocket_uncompress function repeatedly enlarges a file-scope buffer while inflating permessage-deflate data, without limiting total decompressed output. Reaching the flaw requires a negotiated permessage-deflate WebSocket frame in live traffic or a crafted capture file that a user opens; the result is memory exhaustion and process termination.
The record
- CVE
- CVE-2026-6869
- Published
- Apr 30, 2026
- Updated
- Apr 30, 2026
- Vendor
- Wireshark Foundation
- Product
- Wireshark
- Classifications
- CWE-1325, T1204.002
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 30, 2026CVE publishedPublication date reported by the CVE source.
- Apr 30, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=4.4.0 <4.4.15
- Affected versionversion=4.6.0 <4.6.5
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- WebSocket permessage-deflate bomb captureproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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