CVE-2026-26014: 
CBL Mariner vulnerability analysis and mitigation

CVE-2026-26014 is a cryptographic nonce-reuse vulnerability in Pion DTLS, a Go implementation of Datagram Transport Layer Security, where random nonce generation is used with AES-GCM ciphers instead of the deterministic sequence-number-based approach required by best practice. This flaw affects versions v1.0.0 through v3.0.10 and v3.1.0 across all module paths (github.com/pion/dtls, github.com/pion/dtls/v2, and github.com/pion/dtls/v3). The vulnerability was published on February 10–11, 2026, by researcher theodorsm via a GitHub Security Advisory. It carries a CVSS v3.1 base score of 5.9 (Medium) (Github Advisory, Red Hat Bugzilla).

The root cause (CWE-200: Exposure of Sensitive Information to an Unauthorized Actor) lies in the pkg/crypto/ciphersuite package, where the nonce_explicit portion of the AES-GCM nonce was populated using crypto/rand (random bytes) rather than the 64-bit DTLS sequence number as mandated by RFC 9325 §7.2.1. Because the nonce space is only 64 bits and is filled randomly, birthday-bound probability means nonce collisions can occur within a session — a condition known as the "forbidden attack" against GCM. An unauthenticated network attacker who can observe sufficient ciphertext from a session can exploit a repeated nonce to recover the authentication key (GHASH key) and subsequently forge authenticated records. The fix (PR #796) replaces rand.Read with a deterministic construction: seq64 := (uint64(epoch) << 48) | (sequenceNumber & 0x0000ffffffffffff) (Github Advisory, Patch Commit).

Successful exploitation allows a passive or active network attacker to recover the AES-GCM authentication key from a DTLS session, breaking confidentiality of all session traffic and enabling forgery of authenticated DTLS records. The confidentiality impact is rated High, meaning sensitive session data — including any application-layer payloads carried over DTLS (e.g., WebRTC media, IoT telemetry) — can be exposed. Integrity and availability are not directly impacted by this vulnerability, but the ability to spoof authenticated data could enable further attacks depending on the application context (Github Advisory, Red Hat Bugzilla).

The Pion DTLS maintainers have released patched versions: v3.1.1 (primary fix) and v3.0.11 (backport for Go v1.21 compatibility). There are no configuration-based workarounds — upgrading is the only remediation. Organizations should prioritize upgrading all Go modules importing github.com/pion/dtls, github.com/pion/dtls/v2, or github.com/pion/dtls/v3 to the patched versions, particularly in systems handling sensitive data or authentication-critical DTLS communications (Github Advisory, Patch Commit, Backport Commit).

The vulnerability was discovered and reported by theodorsm (the Pion DTLS maintainer) with JoTurk serving as remediation reviewer, indicating responsible internal disclosure. Red Hat tracked the issue via Bugzilla (Bug 2439178) and assigned it medium severity. No significant broader media coverage or notable external researcher commentary has been identified beyond standard vulnerability database aggregation (Red Hat Bugzilla, Github Advisory).