← Vulnerability feed

Vulnerability record · CVE-2026-42764 · published 9 June 2026

CVE-2026-42764: Openssl null pointer dereference vulnerability

OOpenssl · Openssl

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.

7.5 CVSS 3.1 High EPSS 0.78% · top 45.9% CWE-476 · NULL pointer dereference
7.5CVSS 3.1 base score
0.78%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
4References
23 Jul 2026Last modified by NVD

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/openssl/openssl/commit/5e3ed291b8af0b03d5d3b9e56a1da69a187e9729 Patch
https://github.com/openssl/openssl/commit/a45a0aba8095682c88ff4fc4a784892b8c6f0677 Patch
https://github.com/openssl/openssl/commit/bf29a458c1a231eca87e384c62b9c2553fa57a91 Patch
https://openssl-library.org/news/secadv/20260609.txt Vendor Advisory

Track CVE-2026-42764 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

7.5CVE-2014-0160OpenSSL TLS/DTLS Heartbeat Extension Out-of-Bounds Read (Heartbleed)OpenSSL 1.0.1 before 1.0.1g mishandles Heartbeat Extension packets in its TLS and DTLS implementations, causing an out-of-bounds read of process memo…KEVEPSS 100%analysed10.0CVE-2009-3245Openssl improper input validation vulnerabilityOpenSSL before 0.9.8m does not check for a NULL return value from bn_wexpand function calls in (1) crypto/bn/bn_div.c, (2) crypto/bn/bn_gf2m.c, (3) c…EPSS 6.5%10.0CVE-2006-3738OpenSSL SSL_get_shared_ciphers buffer overflow via long cipher listOpenSSL versions before 0.9.7l and 0.9.8d contain a buffer overflow in the SSL_get_shared_ciphers function, triggered by a long list of ciphers. The …EPSS 49%analysed9.8CVE-2026-63073Openssl vulnerabilityIssue summary: OpenSSL CMP response validation passed an unexpected response sender distinguished name directly as the format string to `ERR_raise_da…EPSS 1.2%9.8CVE-2026-31789Openssl out-of-bounds write vulnerabilityIssue summary: Converting an excessively large OCTET STRING value to a hexadecimal string leads to a heap buffer overflow on 32 bit platforms. Impact…EPSS 0.33%9.8CVE-2022-2274OpenSSL 3.0.4 RSA AVX512IFMA memory corruptionOpenSSL 3.0.4 introduced a bug in the RSA implementation for X86_64 CPUs supporting AVX512IFMA instructions, causing 2048-bit private key operations …EPSS 46%analysed9.8CVE-2021-3711OpenSSL SM2 decryption buffer overflowOpenSSL's SM2 decryption code miscalculates the output buffer size needed by EVP_PKEY_decrypt(), so the first sizing call can return a value smaller …EPSS 88%analysed9.8CVE-2016-6309OpenSSL 1.1.0a statem use-after-free on realloc in TLS session handlingOpenSSL 1.1.0a's statem/statem.c fails to account for memory-block movement after a realloc call, leaving a dangling pointer that can be used after f…EPSS 70%analysed

Source: NIST National Vulnerability Database (record CVE-2026-42764), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.