1. Ubuntu Security Notices
  2. USN-8847-1

USN-8847-1: OpenSSL vulnerabilities

Publication date

29 September 2026

Overview

Several security issues were fixed in OpenSSL.

Releases

Packages

  • openssl - Secure Socket Layer (SSL) cryptographic library and tools

Details

It was discovered that OpenSSL incorrectly handled certain certificate
revocation list distribution point names. An attacker could possibly use
this issue to cause OpenSSL to consume excessive memory, resulting in a
denial of service. (CVE-2026-35189)

It was discovered that OpenSSL incorrectly handled QUIC unvalidated
amplification credit accounting. An attacker could possibly use this
issue to cause a denial of service. This issue only affected
Ubuntu 26.04 LTS. (CVE-2026-35191)

It was discovered that OpenSSL incorrectly implemented scalar
multiplication for non-NIST elliptic curves. An attacker could possibly
use this issue to perform a timing side-channel attack and obtain
sensitive information. (CVE-2026-54872)

It was discovered that OpenSSL incorrectly implemented SM2 scalar
multiplication on ARM64...

It was discovered that OpenSSL incorrectly handled certain certificate
revocation list distribution point names. An attacker could possibly use
this issue to cause OpenSSL to consume excessive memory, resulting in a
denial of service. (CVE-2026-35189)

It was discovered that OpenSSL incorrectly handled QUIC unvalidated
amplification credit accounting. An attacker could possibly use this
issue to cause a denial of service. This issue only affected
Ubuntu 26.04 LTS. (CVE-2026-35191)

It was discovered that OpenSSL incorrectly implemented scalar
multiplication for non-NIST elliptic curves. An attacker could possibly
use this issue to perform a timing side-channel attack and obtain
sensitive information. (CVE-2026-54872)

It was discovered that OpenSSL incorrectly implemented SM2 scalar
multiplication on ARM64 and RISC-V architectures. An attacker could
possibly use this issue to perform a timing side-channel attack and
obtain sensitive information. This issue only affected Ubuntu 26.04 LTS.
(CVE-2026-54875)

It was discovered that OpenSSL incorrectly handled SSL context switching
during a TLS handshake. An attacker could possibly use this issue to
cause an out-of-bounds read, resulting in a denial of service or
obtaining sensitive information. This issue only affected Ubuntu 26.04 LTS.
(CVE-2026-72897)

It was discovered that OpenSSL incorrectly enforced QUIC connection-
level flow control for streams. An attacker could possibly use this
issue to cause OpenSSL to consume excessive memory, resulting in a
denial of service. This issue only affected Ubuntu 26.04 LTS.
(CVE-2026-75804)

It was discovered that OpenSSL incorrectly handled a NULL pointer in
CMP client revocation response processing. An attacker could possibly
use this issue to cause a denial of service. (CVE-2026-75805)

It was discovered that OpenSSL incorrectly handled undersized DTLS 1.2
AEAD records before authentication. An attacker could possibly use this
issue to cause a denial of service. (CVE-2026-75806)

It was discovered that OpenSSL incorrectly implemented SM2 signature
generation. An attacker could possibly use this issue to perform a
timing side-channel attack and obtain sensitive information.
(CVE-2026-77696)

It was discovered that OpenSSL incorrectly handled DTLS retransmission
of handshake messages. An attacker could possibly use this issue to
cause incorrect handshake behavior or a denial of service.
(CVE-2026-84782)

It was discovered that OpenSSL incorrectly handled QUIC
RETIRE_CONNECTION_ID frames. An attacker could possibly use this issue
to cause OpenSSL to consume excessive memory, resulting in a denial of
service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-84784)

Update instructions

After a standard system update you need to reboot your computer to make all the necessary changes.

Learn more about how to get the fixes.

The problem can be corrected by updating your system to the following package versions:

Ubuntu Release Package Version
26.04 LTS resolute libssl3t64 –  3.5.5-1ubuntu3.6
24.04 LTS noble libssl3t64 –  3.0.13-0ubuntu3.16
22.04 LTS jammy libssl3 –  3.0.2-0ubuntu1.30

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References

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