Out-of-bounds read/write in HTTP WebSocket upgrade via non-null-terminated Sec-WebSocket-Key

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-5067
StatePUBLISHED
Assignerzephyr
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-06-09 06:16:53 UTC
Updated2026-07-08 13:27:22 UTC
DescriptionA remote, unauthenticated attacker can trigger memory corruption in Zephyr's HTTP server WebSocket upgrade path by sending a crafted Sec-WebSocket-Key header. The HTTP/1 header parser copies the header into a fixed-size buffer using a bounded copy that does not guarantee NUL termination when the input length reaches the buffer size. During upgrade handling the buffer is copied to a local stack buffer and passed to strlen(); if no NUL exists in-bounds, strlen() reads beyond the stack buffer and subsequent concatenation with the WebSocket magic string can write out of bounds. This leads to out-of-bounds read and write on stack memory, resulting in crash (denial of service) and potentially code execution. The path is reachable when CONFIG_HTTP_SERVER_WEBSOCKET is enabled.

Risk And Classification

Primary CVSS: v3.1 9.8 CRITICAL from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS: 0.006430000 probability, percentile 0.464560000 (date 2026-07-09)

Problem Types: CWE-170 | CWE-787 | CWE-170 Improper Null Termination | CWE-787 Out-of-bounds Write

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
3.1CNACVSS9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Zephyrproject Zephyr All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Zephyrproject-rtos Zephyr affected 3.7.0 4.3.0 git Not specified

References

ReferenceSourceLinkTags
github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-wgr4-9pwq-... 134c704f-9b21-4f2e-91b3-4a467353bcc0 github.com Exploit, Patch, Vendor Advisory
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

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