Widely deployed Coturn TURN/STUN server; pre-auth RCE risk via attacker-controlled OAuth token; could disrupt communications across orgs.
CVE-2026-43994
Buffer overflow in coturn OAuth token decode may allow RCE.
Is CVE-2026-43994 being exploited?
Not confirmed. CVE-2026-43994 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.68% probability of exploitation in the next 30 days.
How severe is CVE-2026-43994?
CVE-2026-43994 is rated High with a CVSS score of 8.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-43994?
Yes. A fix has been recorded for CVE-2026-43994. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-43994 affect?
CVE-2026-43994 affects Coturn TURN/STUN server (<4.10.0). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-43994?
Upgrade to 4.10.0+
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Pre-auth RCE via attacker-controlled OAuth token; overflow occurs before AES-GCM auth, possible control-flow corruption; up to 735 bytes written.
Immediate action required
- affected< 4.10.0
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.