NULL Pointer Dereference in QUIC Server Initial Packet Handling

7.5 / 10

HIGH

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

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.

Basic Information

ID CVE-2026-42764

Source openssl

Published Jun 9, 2026 at 16:03

Modified Jun 9, 2026 at 19:37

Affected Product

Vendor OpenSSL

Product OpenSSL

Version 4.0.0

Affected Versions OpenSSL OpenSSL 4.0.0
OpenSSL OpenSSL 3.6.0
OpenSSL OpenSSL 3.5.0

CWE Classification

CWE-476

References

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    "lastseen": "",
    "description": "Issue summary: Receiving a QUIC initial packet with an invalid token may\ntrigger a NULL pointer dereference in the OpenSSL QUIC server with\naddress validation disabled.\n\nImpact summary: NULL pointer dereference typically causes abnormal termination\nof the affected QUIC server process and a Denial of Service.\n\nIf the address validation is disabled in the OpenSSL QUIC server\nimplementation, an attacker can crash the server by sending an initial\npacket with an invalid or expired token.\n\nBy default, the client address validation is enabled in the OpenSSL QUIC server\nimplementation, which makes the default configuration not vulnerable\nto this issue. However if the SSL_LISTENER_FLAG_NO_VALIDATE is used with\nthe SSL_new_listener() call, the address validation is disabled making the\nvulnerable code reachable.\n\nThe FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this\nissue, as the affected code is outside the OpenSSL FIPS module boundary.",
    "published": "2026-06-09T16:03:25.161Z",
    "modified": "2026-06-09T19:37:01.285Z",
    "type": "cve",
    "title": "NULL Pointer Dereference in QUIC Server Initial Packet Handling",
    "source": "openssl",
    "references": "https://openssl-library.org/news/secadv/20260609.txt\nhttps://github.com/openssl/security/commit/bf29a458c1a231eca87e384c62b9c2553fa57a91\nhttps://github.com/openssl/security/commit/a45a0aba8095682c88ff4fc4a784892b8c6f0677\nhttps://github.com/openssl/security/commit/5e3ed291b8af0b03d5d3b9e56a1da69a187e9729",
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NULL Pointer Dereference in QUIC Server Initial Packet Handling_CVE-2026-42764