CVE-2026-27624 — Improper Access Control in Coturn

CWE-284 — Improper Access ControlCWE-441 — Confused Deputy5 documents5 sources
Severity
6.5MEDIUMNVD
CNA7.2OSV7.2
EPSS
0.1%
top 84.17%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
CoturnCoturn Project Coturn
Timeline
PublishedFeb 25

Description

Coturn is a free open source implementation of TURN and STUN Server. Coturn is commonly configured to block loopback and internal ranges using "denied-peer-ip" and/or default loopback restrictions. CVE-2020-26262 addressed bypasses involving "0.0.0.0", "[::1]" and "[::]", but IPv4-mapped IPv6 is not covered. When sending a "CreatePermission" or "ChannelBind" request with the "XOR-PEER-ADDRESS" value of "::ffff:127.0.0.1", a successful response is received, even though "127.0.0.0/8" is blocked vi…

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:NExploitability: 3.9 | Impact: 2.5

Affected Packages2 packages

▶CVEListV5coturn/coturn< 4.9.0

Patches

Patch: github.com ↗

🔴Vulnerability Details

2
OSV
CVE-2026-27624: Coturn is a free open source implementation of TURN and STUN Server↗2026-02-25
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CVEList
Coturn: IPv4-mapped IPv6 (::ffff:0:0/96) bypasses denied-peer-ip ACL↗2026-02-25
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📋Vendor Advisories

1
Debian
CVE-2026-27624: coturn - Coturn is a free open source implementation of TURN and STUN Server. Coturn is c...↗2026
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🕵️Threat Intelligence

1
Wiz
CVE-2026-27624 Impact, Exploitability, and Mitigation Steps | Wiz↗
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CVE-2026-27624 — Improper Access Control in Coturn | cvebase