What’s Vulnerable › Vulnerabilities

CVE-2026-68555: coturn: Chained mobility resumes allow authenticated remote memory exhaustion

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-19 · updated 2026-10-26
• Weakness: CWE-400

Description

Coturn is a free open source implementation of TURN and STUN Server. In 4.15.0, an authenticated TURN user can repeatedly resume one allocation from fresh UDP 5-tuples without completing a handoff when the server enables --mobility. mobile_begin_transition() in src/server/ns_turn_server.c disarms each new session's allocation timeout and overwrites the allocation's single mobile_pending_resume link, leaving earlier pending sessions unreachable by the cleanup path, while copy_auth_parameters() ignores inc_quota() failure. The attacker can therefore retain unbounded server-side sessions and exhaust process memory even when --user-quota=1 is configured. This issue is fixed in version 4.16.0.

Affected products

• coturn: from 4.15.0, < 4.16.0

References

• https://github.com/coturn/coturn/commit/a97f1924bb435bec49d6d91ae01fa2487c2e1bf7
• https://github.com/coturn/coturn/releases/tag/4.16.0
• https://github.com/coturn/coturn/security/advisories/GHSA-hpq3-g7x4-h7xx
• https://github.com/coturn/coturn/security/advisories/GHSA-hpq3-g7x4-h7xx

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