High (7.5) in openssl openssl. EPSS 1.0% chance of exploitation in the next 30 days.
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.
Severity
CVSS 3.1
7.5 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
1.0% chance of exploitation in the next 30 days; higher than 64% of CVEs (scores of 2026-10-31)