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Fencer Vulns
medium 5.3

CVE-2026-34073 json

cryptography has incomplete DNS name constraint enforcement on peer names

published 2026-03-27 7 mo ago modified 2026-10-14 25 d ago also EUVD-2026-17284 , GHSA-m959-cc7f-wv43 , PYSEC-2026-35

cvss
5.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 13%
public exploits
0
none known

Summary

cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Prior to version 46.0.6, DNS name constraints were only validated against SANs within child certificates, and not the "peer name" presented during each validation. Consequently, cryptography would allow a peer named bar.example.com to validate against a wildcard leaf certificate for *.example.com, even if the leaf's parent certificate (or upwards) contained an excluded subtree constraint for bar.example.com. This issue has been patched in version 46.0.6.

Patch / fix

  • pypi cryptography 46.0.6
  • cryptography.io cryptography 46.0.6
  • cryptography_project cryptography 46.0.6
  • python-cryptography_project python-cryptography 46.0.6
  • python-cryptography Debian 14 46.0.6-1

debian advisories DEBIAN-CVE-2026-34073

  • python-cryptography hummingbird 1 46.0.7-1.hum1

red hat advisories RHSA-2026:7295

  • python-cryptography Linux Micro 6.1 42.0.4-slfo.1.1_4.1
  • python-cryptography Linux Micro 6.0 42.0.4-4.1
  • python-cryptography SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 44.0.3-160000.3.1

suse advisories SUSE-SU-2026:21116-1SUSE-SU-2026:21126-1SUSE-SU-2026:21021-1SUSE-SU-2026:21165-1

  • python-cryptography openSUSE Leap 16.0 44.0.3-160000.3.1
  • python-cryptography openSUSE Tumbleweed 46.0.6-1.1

opensuse advisories openSUSE-SU-2026:20506-1openSUSE-SU-2026:10454-1

  • py3-cryptography Alpine 3.24, Alpine 3.23 46.0.7-r0

alpine advisories ALPINE-CVE-2026-34073

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

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-2026-34073 updated cvss 3.7

python-cryptography: Cryptography: Security bypass due to improper DNS name constraint validation

  • Red Hat Lightspeed Core lightspeed-core/rag-tool-rhel9, lightspeed-core/lightspeed-stack-rhel9 Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-ocp-rag-rhel9, openshift-lightspeed/lightspeed-service-api-rhel9 Red Hat Pen Drive Powered by Red Hat Lightspeed pen-drive/pen-drive-scanner-rhel9 Red Hat AI Inference Server rhaiis/vllm-cpu-rhel9, rhaiis/vllm-tpu-rhel9, rhaiis/vllm-cuda-rhel9, rhaiis/vllm-rocm-rhel9, rhaiis-preview/vllm-cuda-rhel9 Red Hat Ansible Automation Platform 2 automation-controller, ansible-automation-platform-26/hub-rhel9, ansible-automation-platform-26/gateway-rhel9, ansible-automation-platform-26/mcp-tools-rhel9, ansible-automation-platform-24/lightspeed-rhel8, ansible-automation-platform-25/lightspeed-rhel8, +8 more Red Hat Ansible Automation Platform Ansible Core 2 ansible-automation-platform/ee-minimal-rhel8, ansible-automation-platform-tech-preview/ee-minimal-rhel8, ansible-automation-platform-tech-preview/ee-minimal-rhel9
    +8 more products
    Red Hat Discovery 2 discovery/discovery-server-rhel9 Red Hat Enterprise Linux 8 fence-agents, fence-agents-all, fence-agents-apc, fence-agents-aws, fence-agents-eps, fence-agents-gce, +43 more Red Hat Enterprise Linux 9 fence-virt, fence-virtd, fence-agents, fence-virtd-cpg, fence-virtd-tcp, fence-agents-all, +51 more Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-cuda-rhel9, rhelai3/bootc-rocm-rhel9, rhelai3/bootc-aws-cuda-rhel9, rhelai3/bootc-gcp-cuda-rhel9, rhelai3/bootc-azure-cuda-rhel9, rhelai3/bootc-azure-rocm-rhel9 Red Hat OpenShift AI (RHOAI) rhoai/odh-mlflow-rhel9, rhoai/odh-vllm-cpu-rhel9, rhoai/odh-vllm-gaudi-rhel9, rhoai/odh-kserve-agent-rhel9, rhoai/odh-kserve-router-rhel9, rhoai/odh-feature-server-rhel9, +24 more Red Hat Quay 3 quay/quay-rhel8, quay/quay-rhel9 Red Hat Satellite 6 satellite/iop-vmaas-rhel9, satellite/foreman-mcp-server-rhel9, satellite/iop-advisor-engine-rhel9, satellite/iop-host-inventory-rhel9, satellite/iop-insights-engine-rhel9 Red Hat Trusted Artifact Signer rhtas/model-transparency-rhel9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Hardened Images python-cryptography 46.0.7-1.hum1
    fixed: vendor fix RHSA-2026:7295
  • Red Hat Hardened Images python3-cryptography 46.0.7-1.hum1
    not affected: vulnerable code not present

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
no
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 13% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 1.7 CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U
GitHub 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CNA 4.0 1.7 CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
OSV 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Affected packages

ecosystem package affected fixed in
pypi cryptography
<46.0.6
46.0.6

Affected products

  • pyca cryptography

Classification

Weakness
  • CWE-295 Improper Certificate Validation

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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.