CVE-2025-15468: Issue summary: If an application using the SSL_CIPHER_find() function in a QUIC protocol client or server receives an unknown cipher suite from the peer, a NULL

Issue summary: If an application using the SSL_CIPHER_find() function in a QUIC protocol client or server receives an unknown cipher suite from the peer, a NULL

Issue summary: If an application using the SSL_CIPHER_find() function in a QUIC protocol client or server receives an unknown cipher suite from the peer, a NULL dereference occurs. Impact summary: A NULL pointer dereference leads to abnormal termination of the running process causing Denial of Service. Some applications call SSL_CIPHER_find() from the client_hello_cb callback on the cipher ID received from the peer. If this is done with an SSL object implementing the QUIC protocol, NULL pointer dereference will happen if the examined cipher ID is unknown or unsupported. As it is not very common to call this function in applications using the QUIC protocol and the worst outcome is Denial of Service, the issue was assessed as Low severity. The vulnerable code was introduced in the 3.2 version with the addition of the QUIC protocol support. The FIPS modules in 3.6, 3.5, 3.4 and 3.3 are not affected by this issue, as the QUIC implementation is outside the OpenSSL FIPS module boundary. OpenSSL 3.6, 3.5, 3.4 and 3.3 are vulnerable to this issue. OpenSSL 3.0, 1.1.1 and 1.0.2 are not affected by this issue.

Description from the National Vulnerability Database, published by openssl-security@openssl.org

What it means for a small business

OpenSSL runs on web servers, so this is mostly your hosting company's to fix. On shared hosting you can't patch it yourself, but you can ask.

Ask your host whether your server runs it, whether it's updated, and on what date. A good host answers that in a day.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.82%, higher than 57% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 29, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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