Medium severity · published Aug 11, 2026
CVE-2026-73213
Coturn: `addr_less_eq()` does a component-wise IPv6 comparison instead of a lexicographic one, letting an authenticated TURN client bypass `denied-peer-ip`/`allowed-peer-ip` IPv6 ranges (TURN-specific SSRF)
5.8
CVSS
0.4%
EPSS
No
On KEV
Description
Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.16.0, addr_less_eq() in src/client/ns_turn_ioaddr.c uses a component-wise comparison for native IPv6 min-max intervals in ioa_addr_in_range(), allowing an authenticated TURN client to relay to an IPv6 peer that is numerically within a configured non-prefix-aligned denied-peer-ip range but is classified as outside it. This issue is fixed in version 4.16.0.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 35% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CO
coturn · coturn
< 4.16.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-73213
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-73213
github.com
https://github.com/coturn/coturn/commit/6c13608c28a04af5d63abddd7565a0dcc4771c28
github.com
https://github.com/coturn/coturn/releases/tag/4.16.0
github.com
https://github.com/coturn/coturn/security/advisories/GHSA-4v97-rxjj-4f99
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