How severe is CVE-2026-39892?

CVE-2026-39892 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-39892 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-39892?

CVE-2026-39892 affects Cryptography.io Cryptography. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-39892?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-39892 have an EU (EUVD) identifier?

Yes. CVE-2026-39892 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-20640.

When was CVE-2026-39892 published?

CVE-2026-39892 was published on 2026-04-08 and last updated on 2026-07-01.

CVE-2026-39892

CVE-2026-39892 is a critical-severity vulnerability in Cryptography.io Cryptography with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-119.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v4: 6.9
EPSS exploit prediction: 1% (47th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-20640
Weakness: CWE-119
Affected product: Cryptography.io Cryptography
Published: 2026-04-08
Last modified: 2026-07-01

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.

Frequently asked questions

What is CVE-2026-39892?: 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.
How severe is CVE-2026-39892?: CVE-2026-39892 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-39892 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-39892?: CVE-2026-39892 affects Cryptography.io Cryptography. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-39892?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-39892 have an EU (EUVD) identifier?: Yes. CVE-2026-39892 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-20640.
When was CVE-2026-39892 published?: CVE-2026-39892 was published on 2026-04-08 and last updated on 2026-07-01.

References

Affected products (1)

cpe:2.3:a:cryptography.io:cryptography:*:*:*:*:*:python:*:*

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