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CRITICAL severity

Cryptography vulnerable to buffer overflow if non-contiguous buffers were passed to APIsGHSA-p423-j2cm-9vmq

CRITICALFix: pyca/cryptography@c09d38a

GHSA-p423-j2cm-9vmq is a critical-severity (CVSS 9.8) Buffer Overflow vulnerability in cryptography. A fix is available for cryptography — see the affected versions and patch details below.

Also known asCVE-2026-39892PYSEC-2026-36
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-p423-j2cm-9vmq.

EPSS Exploitation Probability

via FIRST.org ↗
0.7%probability of exploitation in next 30 days
Lower Risk-0.08%
Lower risk than most CVEs53th percentile — riskier than 53% of all scored CVEsHighest risk
0.00%0.42%0.84%1.26%0.0%0.7%May 26Aug 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected
🐍cryptography

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. From 45.0.0 to before 46.0.7, if a non-contiguous buffer was passed to APIs which accepted Python buffers (e.g. Hash.update()), this could lead to buffer overflows. This vulnerability is fixed in 46.0.7.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPIcryptography≥ 45.0.0&&< 46.0.746.0.7pip install --upgrade 'cryptography==46.0.7'

Affected Products

1 product · 1 configurations
Application
cryptographycryptography.io
≥ 45.0.0 && < 46.0.7
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for cryptography, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update cryptography to 46.0.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-p423-j2cm-9vmq is resolved across your whole dependency graph.

  3. Workarounds

    Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

In default configurations Red Hat products isolate service processes from total system access. Should an attacker be able to exploit this vulnerability their impact will be limited to that service account and they will not have access to the broader system.

Workaround published by Red Hat
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Source: Red Hat security advisory for GHSA-p423-j2cm-9vmq (CC BY 4.0)
ProductFixed inAdvisory
Red Hat Ansible Automation Platform 2.5 for RHEL 8automation-controller-0:4.6.29-2.el8apRHSA-2026:24761
Red Hat Ansible Automation Platform 2.6 for RHEL 9automation-controller-0:4.7.12-1.el9apRHSA-2026:24762
Red Hat AI Inference Server 3.3rhaiis/vllm-rocm-rhel9:1782353093RHSA-2026:30088
Red Hat AI Inference Server 3.3rhaiis/vllm-cuda-rhel9:1782352847RHSA-2026:30089
Red Hat Ansible Automation Platform 2.6ansible-automation-platform-26/controller-rhel9:1779762270RHSA-2026:24866
Red Hat Discovery 2discovery/discovery-server-rhel9:1779395228RHSA-2026:20338
Red Hat Discovery 2discovery/discovery-server-rhel9:1779395228RHSA-2026:26068
Red Hat Enterprise Linux AI 3.3rhelai3/bootc-rocm-rhel9:1784670204RHSA-2026:43651

Frequently Asked Questions

If a non-contiguous buffer was passed to APIs which accepted Python buffers (e.g. `Hash.update()`), this could lead to buffer overflows. For example: ```python h = Hash(SHA256()) b.update(buf[::-1]) ``` would read past the end of the buffer on Python >3.11
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