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OpenAdvisories

Description

Issue summary: The implementations of AES-SIV (RFC 5297) and AES-GCM-SIV
(RFC 8452) mishandle the authentication of AAD (Additional Authenticated
Data) with an empty ciphertext allowing a forgery of such messages.

Impact summary: An attacker can forge empty messages with arbitrary AAD
to the victim's application using these ciphers.

AES-SIV (RFC 5297) and AES-GCM-SIV (RFC 8452) are nonce-misuse-resistant AEAD
modes: they accept a key, nonce, optional AAD (bytes that are authenticated
but not encrypted), and plaintext, and produces ciphertext plus a 16-byte
tag. On decrypt, `EVP_DecryptFinal_ex()` is documented to return success only
if the tag is verified succesfully.

In OpenSSL's provider implementation of these ciphers, the expected tag is
computed only when decryption function is invoked with non-empty data.
If the caller supplies AAD and then calls `EVP_DecryptFinal_ex()` without
invocation of the ciphertext update, which can happen when the received
ciphertext length is zero, the tag is never recalculated and still holds its
all-zeros value.

When AES-GCM-SIV is used, an attacker who sends arbitrary AAD, empty
ciphertext, and all-zeros tag passes authentication under any key they do not
know, single-shot. When AES-SIV is used, for mounting the attack it's
necessary for the application to reuse the decryption context without
resetting the key.

AES-SIV is implemented since OpenSSL 3.0. AES-GCM-SIV is implemented since
OpenSSL 3.2.

No protocols implemented in OpenSSL itself (TLS/CMS/PKCS7/HPKE/QUIC) support
either AES-GCM-SIV or AES-SIV. To mount an attack, the applications must
implement their own protocol and use the EVP interface. Also they must skip the
ciphertext update when a message with an empty ciphertext arrives.

The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this
issue, as these algorithms are not FIPS approved and the affected code is
outside the OpenSSL FIPS module boundary.

Affected products

VendorProductAffectedFixed
OpenSSL OpenSSL 4.0.0 – < 4.0.1, 3.6.0 – < 3.6.3, 3.5.0 – < 3.5.7, 3.4.0 – < 3.4.6, 3.0.0 – < 3.0.21 4.0.1

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 3.6.3-1 —
Debian 13 openssl 3.5.6-1~deb13u2 —
Debian 12 openssl 3.0.20-1~deb12u2 —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 edk2 +1 No fix yet —
Ubuntu 26.04 LTS edk2 +1 No fix yet —
Ubuntu 26.04 LTS openssl 3.5.5-1ubuntu3.2 —
Ubuntu 25.10 edk2 No fix yet —
Ubuntu 25.10 openssl 3.5.3-1ubuntu3.4 —
Ubuntu 24.04 LTS edk2 No fix yet —
Ubuntu 24.04 LTS openssl 3.0.13-0ubuntu3.11 —
Ubuntu 22.04 LTS openssl 3.0.2-0ubuntu1.25 —
Show 4 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro FIPS-updates 24.04 LTS openssl-fips 3.0.13-0ubuntu3.12+Fips1 —
Ubuntu Pro FIPS-updates 22.04 LTS openssl 3.0.2-0ubuntu1.25+Fips1 —
Ubuntu Pro FIPS-updates 22.04 LTS openssl-fips No fix yet —
Ubuntu Pro FIPS-preview 22.04 LTS openssl +1 No fix yet —
Ubuntu Pro 22.04 LTS nodejs No fix yet —
ReleasePackageFixed inAdvisory
RHEL 10 openssl +3 1:3.5.5-4.el10_2 RHSA-2026:25237
RHEL 9 openssl +3 1:3.5.5-4.el9_8 RHSA-2026:25239
Show 1 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Red Hat Hardened Images 1 bootupd +1 0.3.2-1.hum1 RHSA-2026:67551
Red Hat Hardened Images 1 chunkah 0.6.0-3.hum1 RHSA-2026:42825
Red Hat Hardened Images 1 openssl +10 3.5.8-0.1.hum1 RHSA-2026:59641, RHSA-2026:59635
Red Hat Hardened Images 1 python-cryptography +1 50.0.0-1.hum1 RHSA-2026:55543
Red Hat Hardened Images 1 ruby3.3 +5 3.3.10-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 ruby3.4 +5 3.4.10-31.7.hum1 RHSA-2026:62790
Red Hat Hardened Images 1 ruby4.0 +5 4.0.6-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem3.3-bigdecimal 3.1.5-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-bundler 2.5.22-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-devel +1 3.5.22-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-io-console 0.7.1-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-irb 1.13.1-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-json 2.7.2-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-minitest 5.20.0-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-power_assert 2.0.3-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-psych 5.1.2-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-racc 1.7.3-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-rake 13.1.0-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-rbs 3.4.0-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-rdoc 6.6.3.1-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-rexml 3.4.4-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-rss 0.3.1-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-test-unit 3.6.1-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem3.3-typeprof 0.21.9-23.6.hum1 RHSA-2026:62562
Red Hat Hardened Images 1 rubygem4.0-bigdecimal 4.0.1-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-devel +2 4.0.16-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-io-console 0.8.2-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-irb 1.16.0-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-json 2.18.0-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-minitest 6.0.0-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-power_assert 3.0.1-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-psych 5.3.1-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-racc 1.8.1-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-rake 13.3.1-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-rbs 3.10.0-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-rdoc 7.0.4-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-rexml 3.4.4-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-rss 0.3.2-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-test-unit 3.7.5-37.3.hum1 RHSA-2026:62563
Red Hat Hardened Images 1 rubygem4.0-typeprof 0.31.1-37.3.hum1 RHSA-2026:62563

AlmaLinux

Errata ↗
ReleasePackageFixed inAdvisory
AlmaLinux 10 openssl +3 1:3.5.5-4.el10_2.alma.1 ALSA-2026:25237
AlmaLinux 9 openssl +3 1:3.5.5-4.el9_8 ALSA-2026:25239

Rocky Linux

Errata ↗
ReleasePackageFixed inAdvisory
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
ReleasePackageFixed inAdvisory
SLES 15 SP7 openssl-3 3.2.3-150700.5.36.1 SUSE-SU-2026:2648-1
SLES 15 SP6 openssl-3 3.1.4-150600.5.53.1 SUSE-SU-2026:2393-1
SLES 15 SP5 openssl-3 3.0.8-150500.5.66.1 SUSE-SU-2026:2397-1
SLES 15 SP4 openssl-3 3.0.8-150400.4.87.1 SUSE-SU-2026:2598-1
Show 12 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 openssl-3 3.5.0-160000.8.1 SUSE-SU-2026:22315-1
SLES for SAP 15 SP6 openssl-3 3.1.4-150600.5.53.1 SUSE-SU-2026:2393-1
SLES for SAP 15 SP5 openssl-3 3.0.8-150500.5.66.1 SUSE-SU-2026:2397-1
SLES for SAP 15 SP4 openssl-3 3.0.8-150400.4.87.1 SUSE-SU-2026:2598-1
SLES 16.0 openssl-3 3.5.0-160000.8.1 SUSE-SU-2026:22315-1
SLE Micro 6.2 openssl-3 3.5.0-160000.8.1 SUSE-SU-2026:22251-1
SLE Micro 6.1 openssl-3 3.1.4-slfo.1.1_10.1 SUSE-SU-2026:22132-1
SLE Micro 6.0 openssl-3 3.1.4-14.1 SUSE-SU-2026:22100-1
SLE Micro 5.4 openssl-3 3.0.8-150400.4.87.1 SUSE-SU-2026:2598-1
SLE Micro 5.3 openssl-3 3.0.8-150400.4.87.1 SUSE-SU-2026:2598-1
SLE HPC 15 SP5 openssl-3 3.0.8-150500.5.66.1 SUSE-SU-2026:2397-1
SLE HPC 15 SP4 openssl-3 3.0.8-150400.4.87.1 SUSE-SU-2026:2598-1
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed openssl-3 3.5.3-6.1 openSUSE-SU-2026:11023-1
openSUSE Leap 16.0 openssl-3 3.5.0-160000.8.1 openSUSE-SU-2026:21005-1
ReleasePackageFixed inAdvisory
Alpine v3.24 openssl 3.5.7-r0 —
Alpine v3.23 openssl 3.5.7-r0 —
Alpine v3.22 openssl 3.5.7-r0 —
Alpine v3.21 openssl 3.3.7-r1 —

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 openssl +5 1:3.5.5-1.amzn2023.0.5 ALAS2023-2026-1853

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 openssl 3.3.7-3 —
Azure Linux 3 openssl-fips-provider No fix yet —

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 10 openssl +3 1:3.5.5-5.0.1.el10_2 ELSA-2026-25237
Oracle Linux 9 openssl +3 1:3.5.5-4.0.1.el9_8 ELSA-2026-50379, ELSA-2026-25239

Wolfi

ReleasePackageFixed inAdvisory
Wolfi rolling openssl +1 3.6.3-r0 —
Wolfi rolling openssl-4.0 +2 4.0.1-r0 —

Advisories 31

References