Vulnerability · Published Jun 9, 2026 · Assigned by openssl
CVE-2026-34183Unbounded Memory Growth in the QUIC PATH_CHALLENGE Handler
High 7.5
In plain English
A high-severity security flaw in OpenSSL from OpenSSL. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.0% (higher than 64% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | openssl | 1:3.5.5-4.el10_2.alma.1 | ALSA-2026:25237 |
| AlmaLinux:9 | openssl | 1:3.5.5-4.el9_8 | ALSA-2026:25239 |
| AlmaLinux:10 | openssl-devel | 1:3.5.5-4.el10_2.alma.1 | ALSA-2026:25237 |
| AlmaLinux:9 | openssl-devel | 1:3.5.5-4.el9_8 | ALSA-2026:25239 |
| AlmaLinux:10 | openssl-libs | 1:3.5.5-4.el10_2.alma.1 | ALSA-2026:25237 |
| AlmaLinux:9 | openssl-libs | 1:3.5.5-4.el9_8 | ALSA-2026:25239 |
| AlmaLinux:10 | openssl-perl | 1:3.5.5-4.el10_2.alma.1 | ALSA-2026:25237 |
| AlmaLinux:9 | openssl-perl | 1:3.5.5-4.el9_8 | ALSA-2026:25239 |
| Alpine:v3.21 | openssl | 3.3.7-r1 | ALPINE-CVE-2026-34183 |
| Alpine:v3.22 | openssl | 3.5.7-r0 | ALPINE-CVE-2026-34183 |
| Alpine:v3.23 | openssl | 3.5.7-r0 | ALPINE-CVE-2026-34183 |
| Alpine:v3.24 | openssl | 3.5.7-r0 | ALPINE-CVE-2026-34183 |
| Debian:13 | openssl | 3.5.6-1~deb13u2 | DEBIAN-CVE-2026-34183 |
| Debian:14 | openssl | 3.6.3-1 | DEBIAN-CVE-2026-34183 |
| Rocky Linux:10 | openssl | 1:3.5.5-4.el10_2 | RLSA-2026:25237 |
| Rocky Linux:9 | openssl | 1:3.5.5-4.el9_8 | RLSA-2026:25239 |
| Ubuntu:25.10 | edk2 | no fix listed | UBUNTU-CVE-2026-34183 |
| Ubuntu:26.04:LTS | edk2 | no fix listed | UBUNTU-CVE-2026-34183 |
| Ubuntu:26.10 | edk2 | no fix listed | UBUNTU-CVE-2026-34183 |
| Ubuntu:26.04:LTS | edk2-hwe | no fix listed | UBUNTU-CVE-2026-34183 |
| Ubuntu:26.10 | edk2-hwe | no fix listed | UBUNTU-CVE-2026-34183 |
| Ubuntu:25.10 | openssl | 3.5.3-1ubuntu3.4 | UBUNTU-CVE-2026-34183 |
| Ubuntu:26.04:LTS | openssl | 3.5.5-1ubuntu3.2 | UBUNTU-CVE-2026-34183 |
Affected products (as reported)
Weakness: CWE-1325 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- OpenSSL Advisory vendor-advisory
- 4.0.1 git commit patch
- 3.6.3 git commit patch
- 3.5.7 git commit patch
- 3.4.6 git commit patch