Cyber Resilience

CVE-2026-42764

HighUpdated

Published: 09 June 2026

Published
09 June 2026
Modified
17 June 2026
KEV Added
Patch
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0068 48.1th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-42764 is a high-severity NULL Pointer Dereference (CWE-476) vulnerability in Openssl Openssl. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 48.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

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…

more

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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

NULL dereference in QUIC server enables remote DoS via crafted initial packet when address validation disabled (direct application exploitation for endpoint DoS).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-42767Same product: Openssl Openssl
CVE-2025-69421Same product: Openssl Openssl
CVE-2026-42766Same product: Openssl Openssl
CVE-2026-42765Same product: Openssl Openssl
CVE-2026-28389Same product: Openssl Openssl
CVE-2026-28390Same product: Openssl Openssl
CVE-2026-28388Same product: Openssl Openssl
CVE-2026-28386Same product: Openssl Openssl
CVE-2026-42771Same product: Openssl Openssl
CVE-2023-0217Same product: Openssl Openssl

Affected Assets

openssl
openssl
4.0.0 · 3.5.0 — 3.5.7 · 3.6.0 — 3.6.3

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References