CVE-2026-42772

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2026-42772
Issue summary: The QUIC stream reassembly algorithm performance deteriorates progressively as packets are arriving out of order. The worst case has a quadratic complexity proportional to the number of stream frames kept in the buffer for the received stream data. Impact summary: A remote QUIC peer that completes the handshake can create a connection-scoped CPU pressure and potentially a Denial of Service using compliant STREAM frames inside the advertised receive window, with low attacker bandwidth. CWE: CWE-407: Inefficient Algorithmic Complexity Description: OpenSSL manages received QUIC stream fragments using a doubly-linked list. While it optimizes for append operations (at the end of the list), it falls back to a head-to-tail linear search for any fragment that does not immediately follow the current `tail`. By manipulating the sequence of offsets, an attacker can force the server to perform O(n^2) operations, consuming excessive CPU time for the QUIC process. FIPS impact: no The FIPS module is not affected as the QUIC implementation is outside of the OpenSSL FIPS module boundary.

5.3 /10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

References
Link Resource
https://github.com/openssl/openssl/commit/32d0ed8afe1b8c3e7ece725b44663da3d7087a09 Patch
https://github.com/openssl/openssl/commit/ca8402e273af4de5b3f04fa61a0f0c02ce3ae20e Patch
https://github.com/openssl/openssl/commit/eb2becc0a4baea7f3050a247834d0e5c2ebe1773 Patch
https://github.com/openssl/openssl/commit/f42ae513bbda513b3c121d54834040ee4a0eae1a Patch
https://openssl-library.org/news/secadv/20260929.txt Vendor Advisory
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*
History

08 Oct 2026, 01:18

Type Values Removed Values Added
First Time Openssl openssl
Openssl
CPE cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*
References () https://github.com/openssl/openssl/commit/32d0ed8afe1b8c3e7ece725b44663da3d7087a09 - () https://github.com/openssl/openssl/commit/32d0ed8afe1b8c3e7ece725b44663da3d7087a09 - Patch
References () https://github.com/openssl/openssl/commit/ca8402e273af4de5b3f04fa61a0f0c02ce3ae20e - () https://github.com/openssl/openssl/commit/ca8402e273af4de5b3f04fa61a0f0c02ce3ae20e - Patch
References () https://github.com/openssl/openssl/commit/eb2becc0a4baea7f3050a247834d0e5c2ebe1773 - () https://github.com/openssl/openssl/commit/eb2becc0a4baea7f3050a247834d0e5c2ebe1773 - Patch
References () https://github.com/openssl/openssl/commit/f42ae513bbda513b3c121d54834040ee4a0eae1a - () https://github.com/openssl/openssl/commit/f42ae513bbda513b3c121d54834040ee4a0eae1a - Patch
References () https://openssl-library.org/news/secadv/20260929.txt - () https://openssl-library.org/news/secadv/20260929.txt - Vendor Advisory

30 Sep 2026, 21:17

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 5.3

29 Sep 2026, 16:17

Type Values Removed Values Added
New CVE
Information

Published : 2026-09-29 16:17

Updated : 2026-10-08 01:18

NVD link : CVE-2026-42772

Mitre link : CVE-2026-42772

CVE.ORG link : CVE-2026-42772

JSON object : View

Products Affected

openssl

  • openssl
CWE
CWE-407

Inefficient Algorithmic Complexity