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Vulnerability record · CVE-2026-34183 · published 9 June 2026

CVE-2026-34183: Openssl vulnerability

OOpenssl · Openssl

Issue summary: Remote peer may exhaust heap memory of the QUIC server or client by flooding it with packets containing PATH_CHALLENGE frames. Impact summary: A malicious remote peer can cause an unbounded memory allocation which can lead to an abnormal termination of the application acting as a QUIC client or server and a Denial of Service. A remote peer may exhaust heap memory by flooding the local QUIC stack with PATH_CHALLENGE frames. The local QUIC stack allocates a PATH_RESPONSE frame for every PATH_CHALLENGE it receives. The allocated PATH_RESPONSE frame gets freed only when the remote peer acknowledges reception of the PATH_RESPONSE frame which will not be done by a malicious peer. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue. The QUIC stack is outside of OpenSSL FIPS module boundary.

7.5 CVSS 3.1 High EPSS 1.0% · top 37.2% CWE-1325 · CWE-1325
7.5CVSS 3.1 base score
1.0%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
5References
23 Jul 2026Last modified by NVD

Description

Issue summary: Remote peer may exhaust heap memory of the QUIC server or client by flooding it with packets containing PATH_CHALLENGE frames. Impact summary: A malicious remote peer can cause an unbounded memory allocation which can lead to an abnormal termination of the application acting as a QUIC client or server and a Denial of Service. A remote peer may exhaust heap memory by flooding the local QUIC stack with PATH_CHALLENGE frames. The local QUIC stack allocates a PATH_RESPONSE frame for every PATH_CHALLENGE it receives. The allocated PATH_RESPONSE frame gets freed only when the remote peer acknowledges reception of the PATH_RESPONSE frame which will not be done by a malicious peer. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue. The QUIC stack is outside of 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/5b306efb0b3779dfdd0803b4afc9d08c91f11517 Patch
https://github.com/openssl/openssl/commit/7d06955ebe0ecf8adfd4c1e92018586da47ef9ac Patch
https://github.com/openssl/openssl/commit/d2e9efbe4900a373227deb136e8665401404ffac Patch
https://github.com/openssl/openssl/commit/fbaa83859c01ad64f497b757aaf51be7d05ed9eb Patch
https://openssl-library.org/news/secadv/20260609.txt Vendor Advisory

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

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Source: NIST National Vulnerability Database (record CVE-2026-34183), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.