CVE-2026-73213
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`/`all
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.
Published Updated Sources: cvelistV5, GitHub_M
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Unreported
no source claims exploitation
EPSS
0%
chance of exploitation in 30 days
CVSS base
5.8
MEDIUM
CISA SSVC assessment
Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.
Exploitation
PoC
none · proof-of-concept · active
Automatable
No
can an attacker script all four kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component
Affected scope
The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.
Vendors (1)
Products (1)
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 5.8 | CVSS 4.0 | MEDIUM | — | — | cvelistV5 |
Weakness & attack patterns
- CWE-863
Detection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Search application, proxy, and WAF logs for requests touching /client/ns_turn_ioaddr.c.
References
3 on the record
- github.com/coturn/coturn/security/advisories/GHSA-4v97-rxjj-4f99
x_refsource_CONFIRM
- github.com/coturn/coturn/commit/6c13608c28a04af5d63abddd7565a0dcc4771c28
x_refsource_MISC
- github.com/coturn/coturn/releases/tag/4.16.0
x_refsource_MISC
Elsewhere on this site
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.