CVE-2026-39892: cryptography is a package designed to expose cryptographic primitives and recipes to Python developers

Q: How do I fix CVE-2026-39892?

cryptography: upgrade to 46.0.7. Exact commands for each OS are on this page.

Q: Is CVE-2026-39892 being exploited?

CVE-2026-39892 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-39892 affect?

CVE-2026-39892 affects cryptography. Severity is critical (CVSS 9.8). 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 cou

Q: How urgent is CVE-2026-39892?

Priority 52/100. Critical severity; Remotely exploitable, no login, no user action

This month

CRITICAL 9.8REMOTEUPGRADE

CVE-2026-39892 is a critical-severity flaw (CVSS 9.8) affecting cryptography. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 49%)
CISA exploited list	No
Weakness	CWE-119, CWE-131
Published	2026-04-08
Last modified	2026-09-10

Publisher (CNA): GitHub, Inc. · Vendor: cryptography.io

Last updated 2026-09-10 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-08 21:17 UTCPublished CVE record published
2026-09-10 13:20 UTCUpdated Record last modified

cryptography.io cryptography UPGRADE

Affected: >= 45.0.0 and < 46.0.7

Fixed in: 46.0.7

Safe to downgrade to: a release before 45.0.0

1. Check installed version

pip show cryptography

2. UPGRADE to 46.0.7

pip install --upgrade "cryptography>=46.0.7"

3. If no update is available yet, DOWNGRADE to a release before 45.0.0

pip index versions cryptography pip install "cryptography<45.0.0"

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-39892?

cryptography: upgrade to 46.0.7. Exact commands for each OS are on this page.

Is CVE-2026-39892 being exploited?

CVE-2026-39892 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-39892 affect?

CVE-2026-39892 affects cryptography. Severity is critical (CVSS 9.8). 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 cou

How urgent is CVE-2026-39892?

Priority 52/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

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References

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