Skip to content
Fencer Vulns
critical 9.1

CVE-2026-75803 in the critical feed json

AEAD Forgeries with Empty Ciphertext When Using EVP_Cipher()

published 2026-08-25 2 mo ago modified 2026-09-11 58 d ago also EUVD-2026-65488

cvss
9.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 17%
public exploits
0
none known

Summary

Issue summary: ChaCha20-Poly1305 and AES-OCB decryption with an empty ciphertext can report success without verifying the supplied authentication tag when the operation is finalized by calling the EVP_Cipher() function.

Impact summary: Applications calling EVP_Cipher() on an empty ciphertext and expecting the call to check the AEAD tag may accept forged messages.

CWE: CWE-354 (Improper Validation of Integrity Check Value)

Description: The EVP_Cipher() API call for AEAD ciphers behaves like a one shot encryption and decryption call. It also verifies the AEAD tag after the decryption operation. However for AES-OCB and ChaCha20-Poly1305 ciphers it skipped the AEAD tag verification when an empty ciphertext was passed to the function. The callers of this function might believe that a successful return indicates a valid AEAD tag for these ciphers, even when that has not truly been validated in this case.

FIPS impact: no The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this CVE as the affected algorithms are not FIPS approved and thus not implemented in the FIPS module.

Patch / fix

  • OpenSSL OpenSSL 3.0.22, 3.4.7, 3.5.8, 3.6.4, 4.0.2
  • openssl Debian 12 3.0.22-1~deb12u1
  • openssl Debian 13 3.5.7-1~deb13u2
  • openssl Debian 14 3.6.4-1

debian advisories DEBIAN-CVE-2026-75803

  • edk2 Ubuntu 24.04 LTS 2024.02-2ubuntu0.10
  • edk2 Ubuntu 26.04 LTS 2025.11-3ubuntu7.3
  • openssl Ubuntu 22.04 LTS 3.0.2-0ubuntu1.29
  • openssl Ubuntu 24.04 LTS 3.0.13-0ubuntu3.15
  • openssl Ubuntu 26.04 LTS 3.5.5-1ubuntu3.5
  • openssl Ubuntu Pro FIPS-updates 22.04 LTS 3.0.2-0ubuntu1.29+Fips1
  • openssl-fips Ubuntu Pro FIPS-updates 24.04 LTS 3.0.13-0ubuntu3.15+Fips1

ubuntu advisories UBUNTU-CVE-2026-75803

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • ruby3.4 hummingbird 1 3.4.10-31.7.hum1
  • ruby3.4-libs hummingbird 1 3.4.10-31.7.hum1
  • ruby3.4-bundled-gems hummingbird 1 3.4.10-31.7.hum1
  • ruby3.4-default-gems hummingbird 1 3.4.10-31.7.hum1
  • bootupd hummingbird 1 0.2.36-3.hum1
  • rust-bootupd hummingbird 1 0.2.36-3.hum1
  • ruby4.0 hummingbird 1 4.0.6-37.3.hum1
  • ruby4.0-libs hummingbird 1 4.0.6-37.3.hum1

red hat advisories RHSA-2026:62786RHSA-2026:59260RHSA-2026:62563RHSA-2026:62562RHSA-2026:55543RHSA-2026:42825

  • openssl-3 SLE Module for Basesystem 15 SP7 3.5.0-150700.5.50.1
  • openssl-3 SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +3 more 3.0.8-150400.4.98.1
  • openssl-3 Linux Micro 6.0 3.1.4-17.1
  • openssl-3 SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 3.5.0-160000.10.1
  • openssl-3 Linux Micro 6.1 3.1.4-slfo.1.1_13.1
  • openssl-3 SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 3.0.8-150500.5.75.1
  • openssl-3 SLES for SAP 15 SP6, SLES 15 SP6-LTSS 3.1.4-150600.5.64.1

suse advisories SUSE-SU-2026:4039-1SUSE-SU-2026:4032-1SUSE-SU-2026:23473-1SUSE-SU-2026:23463-1SUSE-SU-2026:23609-1SUSE-SU-2026:23512-1

  • openssl-3 openSUSE Leap 16.0 3.5.0-160000.10.1
  • openssl-3 openSUSE Tumbleweed 3.5.3-8.1

opensuse advisories openSUSE-SU-2026:21744-1openSUSE-SU-2026:11623-1

  • openssl AlmaLinux 9 1:3.5.8-1.el9_8
  • openssl-libs AlmaLinux 9 1:3.5.8-1.el9_8
  • openssl-perl AlmaLinux 9 1:3.5.8-1.el9_8

almalinux advisories ALSA-2026:67165

  • openssl Alpine 3.21 3.3.7-r1
  • openssl Alpine 3.24, Alpine 3.23, Alpine 3.22 3.5.8-r0

alpine advisories ALPINE-CVE-2026-75803

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • edk2 Azure Linux 3.0 20240524git3e722403cd16-20
  • openssl Azure Linux 3.0 3.3.7-6

azure linux advisories AZL-97884AZL-97935

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-75803 updated cvss 3.7

openssl: openssl: AEAD forgeries possible with empty ciphertext in EVP_Cipher()

  • Red Hat Ansible Automation Orchestrator 2026 ansible-automation-platform/automation-orchestrator-backend-rhel9 Red Hat Confidential Cluster Operator confidential-clusters-beta/compute-pcrs-rhel9, confidential-clusters-beta/registration-server-rhel9, confidential-clusters-beta/attestation-key-register-rhel9, confidential-clusters-beta/confidential-cluster-rhel9-operator, confidential-clusters-beta/confidential-cluster-operator-bundle Red Hat Confidential Compute Attestation build-of-trustee/trustee-rhel9, agent-sandbox/agent-sandbox-router, openshift-sandboxed-containers/osc-podvm-builder-rhel9, openshift-sandboxed-containers/osc-podvm-payload-rhel9 Red Hat Lightspeed Core lightspeed-core/rag-tool-cpu-rhel9, lightspeed-core/rag-tool-cuda-12.9-rhel9 Red Hat Logging Subsystem for Red Hat OpenShift openshift-logging/vector-rhel9 Red Hat Migration Toolkit for Applications 8 mta/mta-dotnet-external-provider-rhel9
    +22 more products
    Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-ocp-rag-rhel9, openshift-lightspeed-tech-preview/lightspeed-rag-tool-rhel9, openshift-lightspeed/lightspeed-to-dataverse-exporter-rhel9 Red Hat OpenShift Service Mesh 3 openshift-service-mesh/istio-ztunnel-rhel9 Red Hat Pen Drive Powered by Red Hat Lightspeed pen-drive/pen-drive-scanner-rhel9 Red Hat Advanced Cluster Security 4 advanced-cluster-security/rhacs-fact-rhel9 Red Hat Ansible Automation Platform 2 ansible-automation-platform-26/hub-rhel9, ansible-automation-platform-27/hub-rhel9, ansible-automation-platform-26/gateway-rhel9, ansible-automation-platform-27/gateway-rhel9, ansible-automation-platform-26/mcp-tools-rhel9, ansible-automation-platform-27/mcp-tools-rhel9, +20 more Red Hat Ansible Automation Platform Ansible Core 2 ansible-automation-platform/ee-minimal-rhel9, ansible-automation-platform-tech-preview/ee-minimal-rhel9 Red Hat Developer Hub 1 rhdh/rhdh-hub-rhel9, rhdh/rhdh-must-gather-rhel9 Red Hat Directory Server 12 389-ds-base Red Hat Directory Server 13 389-ds-base Red Hat Discovery 2 discovery/discovery-server-rhel9 Red Hat Enterprise Linux 9 ctdb, edk2, ruby, shim, bootc, goose, +88 more Red Hat Enterprise Linux 10 edk2, ruby, shim, bootc, goose, samba, +23 more Red Hat Enterprise Linux command line assistant rhel-cla/rhel-knowledge-bridge-rhel10 Red Hat Offline Knowledge Portal offline-knowledge-portal/rhokp-rhel9, redhat-user-workloads/rhocc-mimir-tenant/mimir/rhokp-core-encrypted Red Hat OpenShift AI (RHOAI) rhoai/odh-feature-server-rhel9, rhoai/odh-pipelines-components-rhel9, rhoai/odh-llm-d-inference-scheduler-rhel9, rhoai/odh-fms-guardrails-orchestrator-rhel9, rhoai/odh-ml-pipelines-runtime-generic-rhel9, rhoai/odh-model-registry-job-async-upload-rhel9, +2 more Red Hat OpenShift Container Platform 4 bootupd, conmon-rs, rpm-ostree, rust-bootupd, kata-containers, rpm-ostree-libs, +1 more Red Hat OpenShift Container Platform 5 conmon-rs, openshift/ose-rhel-coreos-9 Red Hat OpenShift Update Service openshift-update-service/openshift-update-service-rhel8 Red Hat Quay 3 quay/quay-rhel9, redhat-user-workloads/quay-eng-tenant/quay-quay-v3-9 Red Hat Satellite 6 puppet-agent, openvox-agent, satellite/iop-vmaas-rhel9, satellite/iop-advisor-engine-rhel9, satellite/iop-host-inventory-rhel9, satellite/iop-advisor-backend-rhel9, +1 more Red Hat Trusted Artifact Signer rhtas/tuffer-rhel9, rhtas/tuftool-rhel9 Red Hat Trusted Profile Analyzer rhtpa/rhtpa-rhel10, rhtpa/rhtpa-trustification-service-rhel9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux AppStream (v. 9) openssl-perl 3.5.8-1.el9_8 Red Hat Enterprise Linux BaseOS (v. 9) openssl 3.5.8-1.el9_8, openssl-libs 3.5.8-1.el9_8
    fixed: vendor fix RHSA-2026:67165
  • Red Hat Hardened Images chunkah 0.6.0-3.hum1, bootupd 0.2.36-3.hum1, openssl 3.5.8-0.1.hum1, openssl3 3.5.8-0.1.hum1, ruby4.0 4.0.6-37.3.hum1, ruby3.3 3.3.10-23.6.hum1, +20 more
    fixed: vendor fix RHSA-2026:59260
  • Red Hat 3scale API Management Platform 2 3scale-amp2/system-rhel8 Red Hat Advanced Cluster Security 4 advanced-cluster-security/rhacs-fact-rhel8 Red Hat Ansible Automation Platform 2 ansible-automation-platform-24/lightspeed-rhel8, ansible-automation-platform-25/lightspeed-rhel8, ansible-automation-platform-24/ee-supported-rhel8, ansible-automation-platform-25/ee-supported-rhel8, ansible-automation-platform-25/lightspeed-chatbot-rhel8 Red Hat Ansible Automation Platform Ansible Core 2 ansible-automation-platform/ee-minimal-rhel8, ansible-automation-platform-tech-preview/ee-minimal-rhel8 Red Hat Connectivity Link 1 rhcl-1/limitador-rhel9 Red Hat Directory Server 11 389-ds-base
    +3 more products
    Red Hat Enterprise Linux 6 openssl, openssl-perl Red Hat Enterprise Linux 7 ovmf, OVMF, shim, AAVMF, mokutil, openssl, +5 more Red Hat Enterprise Linux 8 edk2, ruby, shim, mozjs60, openssl, ruby-irb, +51 more
    not affected: vulnerable code not present

7 more not affected in the full advisory

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
total
Assessed
2 mo ago

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CNA 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected products

  • OpenSSL OpenSSL

Classification

Weakness
  • CWE-354 Improper Validation of Integrity Check Value
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.