NULL Pointer Dereference in OpenSSL QUIC Server Initial Packet Handling
CVE-2026-42764 is a NULL pointer dereference vulnerability in the OpenSSL QUIC server implementation. The issue is triggered when the server receives a QUIC Initial packet containing an invalid or expired token while client address validation has been disabled. The vulnerable code path is reachable when applications create a listener with SSL_new_listener() using SSL_LISTENER_FLAG_NO_VALIDATE, which disables the default client address validation behavior. In that configuration, malformed token handling during QUIC initial packet processing can dereference a NULL pointer and terminate the server process. The issue affects OpenSSL 4.0.0 before 4.0.1, 3.6.0 before 3.6.3, and 3.5.0 before 3.5.7. The affected code is outside the OpenSSL FIPS module boundary, and the FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected.
Are you exposed to this one?
Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.
Impact, mitigation & remediation
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
If you can’t patch tonight, do this now.
Remediation
Patch, then assume compromise.
Exploits
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Affected products & vendors
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
6 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
An OpenSSL QUIC server NULL pointer dereference vulnerability that can crash the server when it receives an initial packet with an invalid token while client address validation is disabled.
A moderate OpenSSL QUIC server NULL pointer dereference vulnerability reachable when address validation is disabled, allowing denial of service via crafted initial packets.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.