CVE-2026-62959: high-severity vulnerability in coturn
Coturn: Pre-authentication heap memory disclosure in ACME redirect (`try_acme_redirect`)
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.2epss 0.5%
Coturn is a free open source implementation of TURN and STUN Server. From 4.5.2 through 4.14.0, when Coturn is started with --acme-redirect <URL> and exposes a plaintext-TCP listener, an unauthenticated remote client can send a single ordinary HTTP GET request and receive a 301 response whose Location header contains up to ~870 bytes of adjacent process heap memory. The leaked region is a recycled network receive buffer that is reused without being zeroed, so on a busy server it can contain data from other clients' requests (TURN credentials, OAuth tokens, relayed payloads). Root cause is a signed→unsigned conversion. This issue is fixed in version 4.15.0.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Affected products
coturn · coturnRelated CVEs — coturn
In the same product, most dangerous first.
CVE-2020-4067HIGHImproper Initialization in coturnEPSS 1.9%CVE-2020-26262HIGHLoopback bypass in CoturnEPSS 1.5%CVE-2026-40613HIGHCoturn: Misaligned Memory Access in coturn STUN Attribute Parser (Remote DoS on ARM64)EPSS 1.1%CVE-2026-53448HIGHCoturn: SQL Injection in HTTPS Admin Panel Delete OperationsEPSS 0.7%CVE-2026-43994HIGHCoturn: Stack buffer overflow in decode_oauth_token_gcm()EPSS 0.7%CVE-2026-73214HIGHcoturn allocates a full per-peer SSL/session before verifying the DTLS cookie, enabling source-spoofing/botnet state-exhaustion DoSEPSS 0.6%