CVE Catalog

CVE-2026-3446

MediumCVSS 6.0
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.19%

8th percentile - higher than 8% of all known CVEs

Summary

The base64.b64decode() and related functions stop decoding after encountering the first padded quad, even if more data remains. This can lead to acceptance of data that other implementations may process differently. Use validate=True to enforce stricter base64 processing.

Risk Assessment

Inconsistent base64 decoding may result in acceptance of malicious or malformed data that other systems interpret differently. This could lead to validation bypass or data processing errors.

Recommendation

Use base64.b64decode() with validate=True to enforce strict input validation. Review code for places where base64 data is processed without this option.

Related vulnerabilities

Original NVD description (English source)

When calling base64.b64decode() or related functions the decoding process would stop after encountering the first padded quad regardless of whether there was more information to be processed. This can lead to data being accepted which may be processed differently by other implementations. Use "validate=True" to enable stricter processing of base64 data.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS