CVE-2026-42764
NULL Pointer Dereference in QUIC Server Initial Packet Handling
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.
INFO
Published Date :
June 9, 2026, 5:17 p.m.
Last Modified :
June 15, 2026, 6:25 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Ensure client address validation is enabled.
- Avoid using SSL_LISTENER_FLAG_NO_VALIDATE.
- Update OpenSSL to a version that mitigates this issue.
Public PoC/Exploit Available at Github
CVE-2026-42764 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-42764.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-42764 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-42764
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-42764 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-42764 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jun. 15, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:* versions from (including) 3.5.0 up to (excluding) 3.5.7 *cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:* versions from (including) 3.6.0 up to (excluding) 3.6.3 *cpe:2.3:a:openssl:openssl:4.0.0:-:*:*:*:*:*:* Added Reference Type OpenSSL Software Foundation: https://github.com/openssl/openssl/commit/5e3ed291b8af0b03d5d3b9e56a1da69a187e9729 Types: Patch Added Reference Type OpenSSL Software Foundation: https://github.com/openssl/openssl/commit/a45a0aba8095682c88ff4fc4a784892b8c6f0677 Types: Patch Added Reference Type OpenSSL Software Foundation: https://github.com/openssl/openssl/commit/bf29a458c1a231eca87e384c62b9c2553fa57a91 Types: Patch Added Reference Type OpenSSL Software Foundation: https://openssl-library.org/news/secadv/20260609.txt Types: Vendor Advisory -
CVE Modified by [email protected]
Jun. 10, 2026
Action Type Old Value New Value Added Reference https://github.com/openssl/openssl/commit/5e3ed291b8af0b03d5d3b9e56a1da69a187e9729 Added Reference https://github.com/openssl/openssl/commit/a45a0aba8095682c88ff4fc4a784892b8c6f0677 Added Reference https://github.com/openssl/openssl/commit/bf29a458c1a231eca87e384c62b9c2553fa57a91 Removed Reference https://github.com/openssl/security/commit/5e3ed291b8af0b03d5d3b9e56a1da69a187e9729 Removed Reference https://github.com/openssl/security/commit/a45a0aba8095682c88ff4fc4a784892b8c6f0677 Removed Reference https://github.com/openssl/security/commit/bf29a458c1a231eca87e384c62b9c2553fa57a91 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 09, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H -
New CVE Received by [email protected]
Jun. 09, 2026
Action Type Old Value New Value Added 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. Added CWE CWE-476 Added Reference https://github.com/openssl/security/commit/5e3ed291b8af0b03d5d3b9e56a1da69a187e9729 Added Reference https://github.com/openssl/security/commit/a45a0aba8095682c88ff4fc4a784892b8c6f0677 Added Reference https://github.com/openssl/security/commit/bf29a458c1a231eca87e384c62b9c2553fa57a91 Added Reference https://openssl-library.org/news/secadv/20260609.txt