Vulnerability · Published Jun 9, 2026 · Assigned by openssl
CVE-2026-42764NULL Pointer Dereference in QUIC Server Initial Packet Handling
High 7.5
In plain English
A high-severity null pointer dereference in OpenSSL from OpenSSL. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.2% (higher than 67% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Issue summary: Receiving a QUIC initial packet with an invalid token may trigger a NULL pointer dereference in the OpenSSL QUIC server with address validation disabled. Impact summary: NULL pointer dereference typically causes abnormal termination of the affected QUIC server process and a Denial of Service. If the address validation is disabled in the OpenSSL QUIC server implementation, an attacker can crash the server by sending an initial packet with an invalid or expired token. By default, the client address validation is enabled in the OpenSSL QUIC server implementation, which makes the default configuration not vulnerable to this issue. However if the SSL_LISTENER_FLAG_NO_VALIDATE is used with the SSL_new_listener() call, the address validation is disabled making the vulnerable code reachable. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | openssl | 1:3.5.5-4.el10_2.alma.1 | ALSA-2026:25237 |
| AlmaLinux:9 | openssl | 1:3.5.5-4.el9_8 | ALSA-2026:25239 |
| AlmaLinux:10 | openssl-devel | 1:3.5.5-4.el10_2.alma.1 | ALSA-2026:25237 |
| AlmaLinux:9 | openssl-devel | 1:3.5.5-4.el9_8 | ALSA-2026:25239 |
| AlmaLinux:10 | openssl-libs | 1:3.5.5-4.el10_2.alma.1 | ALSA-2026:25237 |
| AlmaLinux:9 | openssl-libs | 1:3.5.5-4.el9_8 | ALSA-2026:25239 |
| AlmaLinux:10 | openssl-perl | 1:3.5.5-4.el10_2.alma.1 | ALSA-2026:25237 |
| AlmaLinux:9 | openssl-perl | 1:3.5.5-4.el9_8 | ALSA-2026:25239 |
| Alpine:v3.22 | openssl | 3.5.7-r0 | ALPINE-CVE-2026-42764 |
| Alpine:v3.23 | openssl | 3.5.7-r0 | ALPINE-CVE-2026-42764 |
| Alpine:v3.24 | openssl | 3.5.7-r0 | ALPINE-CVE-2026-42764 |
| Debian:13 | openssl | 3.5.6-1~deb13u2 | DEBIAN-CVE-2026-42764 |
| Debian:14 | openssl | 3.6.3-1 | DEBIAN-CVE-2026-42764 |
| Rocky Linux:10 | openssl | 1:3.5.5-4.el10_2 | RLSA-2026:25237 |
| Rocky Linux:9 | openssl | 1:3.5.5-4.el9_8 | RLSA-2026:25239 |
| Ubuntu:26.04:LTS | edk2 | no fix listed | UBUNTU-CVE-2026-42764 |
| Ubuntu:26.10 | edk2 | no fix listed | UBUNTU-CVE-2026-42764 |
| Ubuntu:26.04:LTS | edk2-hwe | no fix listed | UBUNTU-CVE-2026-42764 |
| Ubuntu:26.10 | edk2-hwe | no fix listed | UBUNTU-CVE-2026-42764 |
| Ubuntu:25.10 | openssl | 3.5.3-1ubuntu3.4 | UBUNTU-CVE-2026-42764 |
| Ubuntu:26.04:LTS | openssl | 3.5.5-1ubuntu3.2 | UBUNTU-CVE-2026-42764 |
Affected products (as reported)
Weakness: CWE-476 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- OpenSSL Advisory vendor-advisory
- 4.0.1 git commit patch
- 3.6.3 git commit patch
- 3.5.7 git commit patch