CVE-2026-73213Public exploitNetwork attack vectorHinoki check available

Authenticated IPv6 SSRF via component-wise range comparison

Published Aug 11, 2026 · Updated Aug 11, 2026

SSRF in coturn before 4.16.0 allows remote authenticated users to relay traffic to an IPv6 peer blocked by a configured deny range. The addr_less_eq() routine in src/client/ns_turn_ioaddr.c compares all 16 address bytes independently, so ioa_addr_in_range() treats a numeric interval as a per-byte box and under-matches addresses inside it. Exploitation requires a non-prefix-aligned native IPv6 min-max rule and a useful denied peer reachable from the server; exact-address and ordinary prefix-aligned controls are unaffected.

CVSS severity5.8
Medium
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

SSRF in coturn before 4.16.0 allows remote authenticated users to relay traffic to an IPv6 peer blocked by a configured deny range. The addr_less_eq() routine in src/client/ns_turn_ioaddr.c compares all 16 address bytes independently, so ioa_addr_in_range() treats a numeric interval as a per-byte box and under-matches addresses inside it. Exploitation requires a non-prefix-aligned native IPv6 min-max rule and a useful denied peer reachable from the server; exact-address and ordinary prefix-aligned controls are unaffected.

The record

CVE
CVE-2026-73213
Published
Aug 11, 2026
Updated
Aug 11, 2026
Vendor
coturn
Product
coturn
Classifications
CWE-863, T1090
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 4.16.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

coturn · coturnversion=< 4.16.0

Published CVSS scores

5.8GitHubCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1090Proxy

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo