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OpenAdvisories
Unscored CVE-2026-95691 EUVD-2026-121636GHSA-q8c3-jq6j-fc5f

Issue summary: A retransmitted QUIC CRYPTO frame can release packet storage while the TLS record layer retains a direct pointer into that s…

Published Nov 10, 2026 · Assigned by openssl

Description

Issue summary: A retransmitted QUIC CRYPTO frame can release packet storage
while the TLS record layer retains a direct pointer into that storage causing
use after free.

Impact summary: A malicious QUIC server can cause a heap-use-after-free read
in the OpenSSL QUIC client. The server can also identify one allocator-adjacent
byte through the client's protected Handshake response.

CWE: CWE-416: Use After Free

Description: During CRYPTO stream processing, a pointer into the first frame's
memory on the stream is lent to the TLS handshake processing. The memory
must remain stable until it is processed and released. However the processing
of retransmitted CRYPTO frames could release the memory if the retransmitted
frame fully overlapped the existing frame. This then causes use-after-free read
when the TLS handshake processing continues.

The use-after-free read can lead to a Denial-of-Service of the client
application or a minor leak of information about the heap memory contents
that might be overwritten with other data, subsequently allocated by
the application, to the peer.

FIPS impact: no
The FIPS module is not affected as the QUIC implementation is outside of
the OpenSSL FIPS module boundary.

Affected products

VendorProductAffectedFixed
OpenSSL OpenSSL 4.1.0 <4.1.1 —
OpenSSL OpenSSL 4.0.0 <4.0.4 —
OpenSSL OpenSSL 3.5.0 <3.5.10 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 openssl No fix yet —
Debian 13 openssl No fix yet —
Debian 12 openssl No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 edk2 +2 No fix yet —
Ubuntu 26.04 LTS edk2 +2 No fix yet —
Ubuntu 24.04 LTS edk2 +1 No fix yet —
Ubuntu 22.04 LTS edk2 +1 No fix yet —
Show 14 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro FIPS 20.04 LTS openssl No fix yet —
Ubuntu Pro FIPS 18.04 LTS openssl No fix yet —
Ubuntu Pro FIPS 16.04 LTS openssl No fix yet —
Ubuntu Pro FIPS-updates 24.04 LTS openssl-fips No fix yet —
Ubuntu Pro FIPS-updates 22.04 LTS openssl +1 No fix yet —
Ubuntu Pro FIPS-updates 20.04 LTS openssl No fix yet —
Ubuntu Pro FIPS-updates 18.04 LTS openssl No fix yet —
Ubuntu Pro FIPS-updates 16.04 LTS openssl No fix yet —
Ubuntu Pro FIPS-preview 22.04 LTS openssl +1 No fix yet —
Ubuntu Pro 22.04 LTS nodejs No fix yet —
Ubuntu Pro 20.04 LTS edk2 +1 No fix yet —
Ubuntu Pro 18.04 LTS edk2 +3 No fix yet —
Ubuntu Pro 16.04 LTS edk2 +2 No fix yet —
Ubuntu Pro 14.04 LTS openssl No fix yet —

Advisories 1

References