libre is a generic library for real-time communications with asynchronous input and output support. Prior to 4.8.1, the websock_decode() function in src/websock/websock.c contains an integer overflow when validating a masked WebSocket frame that uses the 64-bit extended length encoding. The expression 4 + hdr->len can wrap when hdr->len is close to UINT64_MAX, causing the mbuf_get_left() bounds check to pass. The subsequent XOR unmasking loop then writes beyond the heap buffer. Applications using websock_accept() or websock_accept_proto() to implement a WebSocket server are affected, and exploitation can cause attacker-controlled heap corruption or denial of service after the HTTP WebSocket upgrade handshake. This issue is fixed in version 4.8.1.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
baresip re affected
Version Status Constraints
< 4.8.1 affected —

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Project Subscriptions

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Advisories

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Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/baresip/re/commit/718b92615c7963670d26c1a2b246968b58d782e8 cve-icon cve-icon
https://github.com/baresip/re/pull/1584 cve-icon cve-icon
https://github.com/baresip/re/releases/tag/v4.8.1 cve-icon cve-icon
https://github.com/baresip/re/security/advisories/GHSA-hvxv-v2gp-v93h cve-icon cve-icon
History

Tue, 18 Aug 2026 18:00:00 +0000

Type Values Removed Values Added
Description libre is a generic library for real-time communications with asynchronous input and output support. Prior to 4.8.1, the websock_decode() function in src/websock/websock.c contains an integer overflow when validating a masked WebSocket frame that uses the 64-bit extended length encoding. The expression 4 + hdr->len can wrap when hdr->len is close to UINT64_MAX, causing the mbuf_get_left() bounds check to pass. The subsequent XOR unmasking loop then writes beyond the heap buffer. Applications using websock_accept() or websock_accept_proto() to implement a WebSocket server are affected, and exploitation can cause attacker-controlled heap corruption or denial of service after the HTTP WebSocket upgrade handshake. This issue is fixed in version 4.8.1.
Title libre: Integer overflow in websock_decode() masked frame length check leads to heap buffer overflow
Weaknesses CWE-190
CWE-787
References
Metrics cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-18T17:53:01.696Z

Reserved: 2026-06-03T20:54:20.432Z

Link: CVE-2026-50161

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-18T18:17:53.380

Modified: 2026-08-18T18:17:53.380

Link: CVE-2026-50161

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-18T20:15:04Z

Weaknesses