GHSA-w7pp-m8wf-vj6r is a medium-severity (CVSS 6.5) CWE-754 vulnerability in cryptography. 1 public exploit reference exists, so weaponization risk is real. A fix is available for cryptography — see the affected versions and patch details below.
Cipher.update_into can corrupt memory if passed an immutable python object as the outbuf
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-w7pp-m8wf-vj6r.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-w7pp-m8wf-vj6r plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,238 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
cryptographyReal-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
Previously, Cipher.update_into would accept Python objects which implement the buffer protocol, but provide only immutable buffers:
>>> outbuf = b"\x00" * 32
>>> c = ciphers.Cipher(AES(b"\x00" * 32), modes.ECB()).encryptor()
>>> c.update_into(b"\x00" * 16, outbuf)
16
>>> outbuf
b'\xdc\x95\xc0x\xa2@\x89\x89\xadH\xa2\x14\x92\x84 \x87\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
This would allow immutable objects (such as bytes) to be mutated, thus violating fundamental rules of Python. This is a soundness bug -- it allows programmers to misuse an API, it cannot be exploited by attacker controlled data alone.
This now correctly raises an exception.
This issue has been present since update_into was originally introduced in cryptography 1.8.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | cryptography | ≥ 1.8&&< 39.0.1 | 39.0.1pip install --upgrade 'cryptography==39.0.1' |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
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.
Fix
Update cryptography to 39.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-w7pp-m8wf-vj6r is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-w7pp-m8wf-vj6r can be triaged on real exposure rather than presence alone.
Tailored to GHSA-w7pp-m8wf-vj6r. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
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.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Ansible Automation Platform 2.4 for RHEL 8 | python3x-cryptography-0:38.0.4-2.el8ap | RHSA-2023:4693 |
| Red Hat Ansible Automation Platform 2.4 for RHEL 8 | automation-controller-0:4.4.3-1.el8ap | RHSA-2023:4971 |
| Red Hat Enterprise Linux 8 | python39:3.9-8100020240214182535.7044f6c1 | RHSA-2024:2985 |
| Red Hat Enterprise Linux 8 | python-cryptography-0:3.2.1-6.el8 | RHSA-2023:7096 |
| Red Hat Enterprise Linux 9 | python-cryptography-0:36.0.1-4.el9 | RHSA-2023:6615 |
| Red Hat Quay 3 | quay/quay-rhel8:v3.10.0-150 | RHSA-2023:7341 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7 | rh-python38-python-cryptography-0:2.8-6.el7 | RHSA-2023:6793 |
Frequently Asked Questions
Is GHSA-w7pp-m8wf-vj6r in your dependencies?
O3 Security finds GHSA-w7pp-m8wf-vj6r across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.