CVE catalog
CVE-2026-68553
Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.13.0, an authenticated TURN user can place printf-style format specifiers in the STUN USERNAME or REALM attribute, which
- Severity
- High · CVSS 7.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H - Published
- Updated
- Source
- [NVD] · [CVE record]
- EPSS
- 0.48% · Oct 25, 2026
Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.13.0, an authenticated TURN user can place printf-style format specifiers in the STUN USERNAME or REALM attribute, which passes is_secure_string() validation and is embedded into Redis keys at nine call sites in src/apps/relay/ns_ioalib_engine_impl.c. send_message_to_redis() in src/apps/relay/hiredis_libevent2.c then passes the attacker-controlled key as the format argument to redisAsyncCommand() while supplying only one variadic value, causing hiredis redisvFormatCommand() to read past the va_list. Exploitation can crash the coturn process and terminate active TURN sessions or disclose stack memory into Redis. This issue is fixed in version 4.13.0.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | coturn | sid | 4.18.0-1 | fixed |
| Debian | coturn | forky | 4.18.0-1 | fixed |
| Debian | coturn | trixie | 4.6.1-2 | vulnerable |
| Debian | coturn | bookworm | 4.6.1-1 | vulnerable |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | coturn | source | sid | 4.14.0-1 | not yet assigned | Not reported | Not reported |
| Debian | coturn | source | forky | 4.14.0-1 | not yet assigned | Not reported | Not reported |
| Debian | coturn | source | trixie | (unfixed) | not yet assigned | Not reported | Not reported |
| Debian | coturn | source | bookworm | (unfixed) | not yet assigned | Not reported | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [coturn]Affected
Details (2)
4.6.1-1· amd64 · bookwormAffected
nvd · coturn · debian · bookworm; nvd · coturn · debian · 12
4.6.1-1· arm64 · bookwormAffected
nvd · coturn · debian · bookworm; nvd · coturn · debian · 12
[Debian 13 (Trixie)]
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_11617-1.json]
- [https://github.com/coturn/coturn/commit/8fa38032bb4751e11e072d65a8eca3c06c950979]
- [https://github.com/coturn/coturn/releases/tag/4.13.0]
- [https://github.com/coturn/coturn/security/advisories/GHSA-4g7c-p5wg-j4hp]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-68553]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-68553]
- [https://security-tracker.debian.org/tracker/CVE-2026-68553]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68553.json]
[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]