The vulnerability stems from missing host name verification for server TLS certificates in JetBrains IntelliJ IDEA versions prior to 2026.3. Because the client does not check that the certificate presented by a server matches the expected host name, an adversary could substitute a fraudulent certificate and appear legitimate to the IDE. This flaw can potentially expose sensitive data, grant unauthorized access to remote repositories or build servers, and undermine the integrity of the development environment. The weakness is a classic example of a certificate validation bypass, mapped to CWE-297.

JetBrains IntelliJ IDEA users running a version earlier than 2026.3 are affected. No additional vendors or product variants are listed.

The CVSS score of 7.4 indicates a high impact with a medium risk of exploitation in the security community. EPSS data is not available, making concrete predictions about actual attack frequency uncertain, but the absence of host name verification is a known vector for man‑in‑the‑middle attacks in similar contexts. The vulnerability is not currently listed in CISA’s KEV catalog, so it has not been observed as a widely exploited flaw, yet its impact justifies immediate action. A potential attacker would need network access to the IntelliJ IDEA session or the remote server it contacts, making the attack vector likely remote but still significant for open or misconfigured environments.