NVD / CVE Program· CNA GitHub_M

CVE-2026-34073: cryptography has incomplete DNS name constraint enforcement on peer names

Noroxi assessment

Priority: Monitor (action score 6/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.22% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
Fixed version: pyca cryptography 46.0.6.

Low priority for now. Upgrade to pyca cryptography 46.0.6 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

LowCVSS 1.7 · v4.0—No exploit Fix available

Published: Mar 31, 2026
Updated: Oct 14, 2026
EPSS: 0.2% · 12th percentile
CWE: CWE-295

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 6 / 40 · 1.7 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · GitHub_M: 1.7; NVD has not scored this yet; the score shown is the CNA’s.

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
cryptography.io	cryptography	cpe:2.3:a:cryptography.io:cryptography

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This vulnerability is about certificate validation or weak cryptography. The free SSL checker tests your certificate, enabled TLS versions and weak ciphers.

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Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

cryptography.io cryptographybefore 46.0.6

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

pyca cryptography
- < 46.0.6affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Alpine:v3.23	py3-cryptography	before 46.0.7-r0	46.0.7-r0
Debian:12	python-cryptography	from 0	—
Debian:14	python-cryptography	before 46.0.6-1	46.0.6-1
openSUSE:Leap 16.0	python-cryptography	before 44.0.3-160000.3.1	44.0.3-160000.3.1
openSUSE:Tumbleweed	python-cryptography	before 46.0.6-1.1	46.0.6-1.1
PyPI	cryptography	before 46.0.6	46.0.6
Red Hat:hummingbird:1	python-cryptography	before 0:46.0.7-1.hum1	0:46.0.7-1.hum1
SUSE:Linux Micro 6.0	python-cryptography	before 42.0.4-4.1	42.0.4-4.1
SUSE:Linux Micro 6.1	python-cryptography	before 42.0.4-slfo.1.1_4.1	42.0.4-slfo.1.1_4.1
SUSE:Linux Micro 6.2	python-cryptography	before 44.0.3-160000.3.1	44.0.3-160000.3.1

Same product

cryptography.io: all records

Other highest-scoring records for the same primary product.

CVE-2020-36242In the cryptography package before 3.3.2 for Python, certain sequences of update calls to symmetrically encrypt multi-GB values could result
38Monitor
CVE-2026-26007cryptography Subgroup Attack Due to Missing Subgroup Validation for SECT Curves
32Monitor
CVE-2016-9243HKDF in cryptography before 1.5.2 returns an empty byte-string if used with a length less than algorithm.digest_size.
31Monitor

Published before and after this one in the same product

← EarlierCVE-2023-49083Nov 29, 2023 · cryptography vulnerable to NULL-dereference when loading PKCS7 certificates
30Monitor
← EarlierCVE-2024-26130Feb 21, 2024 · cryptography NULL pointer deference with pkcs12.serialize_key_and_certificates when called with a non-matching certificate and private key and an hmac_hash over
30Monitor
Later →CVE-2026-39892Apr 8, 2026 · cryptography has a buffer overflow if non-contiguous buffers were passed to APIs
27Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
pyca cryptography	46.0.6 · description	Vendor (CNA)
alpine:py3-cryptography	46.0.7-r0 · Alpine:v3.23	Package registry (OSV)
debian:python-cryptography	46.0.6-1 · Debian:14	Package registry (OSV)
opensuse:python-cryptography	46.0.6-1.1 · openSUSE:Tumbleweed	Package registry (OSV)
PyPI:cryptography	46.0.6	Package registry (OSV)
red hat:python-cryptography	0:46.0.7-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
suse:python-cryptography	44.0.3-160000.3.1 · SUSE:Linux Micro 6.2	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
Special conditions such as timing or configuration are required.

If successful

Confidentiality
Integrity
Availability

Attack vector: Network
Attack complexity: High
Privileges required: None
User interaction: None
Scope: X

Weakness class (CWE)

CWE-295 · Improper Certificate Validation

CVSS vector

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-secondary

Root cause

A certificate validation error is silently swallowed instead of terminating the connection. Often, code added for a test environment makes its way into production.

The bug in code

The whole CWE-295 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

kotlin

1override fun checkServerTrusted(chain: Array<X509Certificate>, type: String) {
2  // Left empty for the test environment
3}

Fixed

kotlin

1val client = OkHttpClient.Builder()
2  .certificatePinner(
3    CertificatePinner.Builder()
4      .add("api.sirius.example", "sha256/…")
5      .build()
6  ).build()