# CVE-2026-3446: Base64 decoding stops at first padded quad by default CVE-2026-3446 is fixed in 22 products on 2 platforms, first by Python 3.13 3.13.13, released April 7, 2026. 9 other affected products have no fix yet. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2026-3446 - Priority: Routine - CVSS: 6.0 (moderate) - EPSS: 0.0018 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Apr 10, 2026 - Weakness: CWE-345: Insufficient Verification of Data Authenticity - Vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-3446 ## Description 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. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Windows apps | Python 3.13 | 3.13.13 | [Python 3.13 3.13.13](https://patchblox.com/security/data/fix/windows-app/python.python.3.13-3.13.13.md) | Apr 7, 2026 | | Windows apps | Python 3.14 | 3.14.4 | [Python 3.14 3.14.4](https://patchblox.com/security/data/fix/windows-app/python.python.3.14-3.14.4.md) | Apr 7, 2026 | | Linux | python sles 15.7 | 2.7.18-150000.117.1 | [SUSE-SU-2026:1503-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1503-1.md) | Apr 20, 2026 | | Linux | python-base sles 15.7 | 2.7.18-150000.117.1 | [SUSE-SU-2026:1503-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1503-1.md) | Apr 20, 2026 | | Linux | python-unversioned-command amzn 2023 | 3.9.25-1.amzn2023.0.7 | [ALAS2023-2026-1933](https://patchblox.com/security/data/fix/linux/alas2023-2026-1933.md) | Jul 6, 2026 | | Linux | python3 amzn 2023 | 3.9.25-1.amzn2023.0.7 | [ALAS2023-2026-1933](https://patchblox.com/security/data/fix/linux/alas2023-2026-1933.md) | Jul 6, 2026 | | Linux | python3 opensuse-leap 16.0 | 3.13.14-160000.1.1 | [OPENSUSE-SU-2026:21459-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21459-1.md) | Jul 28, 2026 | | Linux | python3 sles 15.6 | 3.6.15-150300.10.129.1 | [SUSE-SU-2026:4754-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4754-1.md) | Nov 7, 2026 | | Linux | python3 sles 15.7 | 3.6.15-150300.10.129.1 | [SUSE-SU-2026:4754-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4754-1.md) | Nov 7, 2026 | | Linux | python3-core sles 15.6 | 3.6.15-150300.10.129.1 | [SUSE-SU-2026:4754-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4754-1.md) | Nov 7, 2026 | | Linux | python3-core sles 15.7 | 3.6.15-150300.10.129.1 | [SUSE-SU-2026:4754-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4754-1.md) | Nov 7, 2026 | | Linux | python3-debug amzn 2023 | 3.9.25-1.amzn2023.0.7 | [ALAS2023-2026-1933](https://patchblox.com/security/data/fix/linux/alas2023-2026-1933.md) | Jul 6, 2026 | | Linux | python3-devel amzn 2023 | 3.9.25-1.amzn2023.0.7 | [ALAS2023-2026-1933](https://patchblox.com/security/data/fix/linux/alas2023-2026-1933.md) | Jul 6, 2026 | | Linux | python3-idle amzn 2023 | 3.9.25-1.amzn2023.0.7 | [ALAS2023-2026-1933](https://patchblox.com/security/data/fix/linux/alas2023-2026-1933.md) | Jul 6, 2026 | | Linux | python3-libs amzn 2023 | 3.9.25-1.amzn2023.0.7 | [ALAS2023-2026-1933](https://patchblox.com/security/data/fix/linux/alas2023-2026-1933.md) | Jul 6, 2026 | | Linux | python3-test amzn 2023 | 3.9.25-1.amzn2023.0.7 | [ALAS2023-2026-1933](https://patchblox.com/security/data/fix/linux/alas2023-2026-1933.md) | Jul 6, 2026 | | Linux | python3-tkinter amzn 2023 | 3.9.25-1.amzn2023.0.7 | [ALAS2023-2026-1933](https://patchblox.com/security/data/fix/linux/alas2023-2026-1933.md) | Jul 6, 2026 | | Linux | python3.13 Debian 13.5 (trixie) | 3.13.5-2+deb13u2 | [DEBIAN-CVE-2026-3446](https://patchblox.com/security/data/fix/linux/debian-cve-2026-3446.md) | Apr 10, 2026 | | Linux | python3.14 Debian 14 | 3.14.4-1 | [DEBIAN-CVE-2026-3446](https://patchblox.com/security/data/fix/linux/debian-cve-2026-3446.md) | Apr 10, 2026 | | Linux | python3.9-debuginfo amzn 2023 | 3.9.25-1.amzn2023.0.7 | [ALAS2023-2026-1933](https://patchblox.com/security/data/fix/linux/alas2023-2026-1933.md) | Jul 6, 2026 | | Linux | python3.9-debugsource amzn 2023 | 3.9.25-1.amzn2023.0.7 | [ALAS2023-2026-1933](https://patchblox.com/security/data/fix/linux/alas2023-2026-1933.md) | Jul 6, 2026 | | Linux | python313 opensuse-leap 16.0 | 3.13.14-160000.1.1 | [OPENSUSE-SU-2026:21459-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21459-1.md) | Jul 28, 2026 | | Linux | python313 sles 15.7 | 3.13.13-150700.4.50.1 | [SUSE-SU-2026:2464-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2464-1.md) | Jun 19, 2026 | | Linux | python313-core opensuse-leap 16.0 | 3.13.14-160000.1.1 | [OPENSUSE-SU-2026:21459-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21459-1.md) | Jul 28, 2026 | | Linux | python313-core sles 15.7 | 3.13.13-150700.4.50.1 | [SUSE-SU-2026:2464-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2464-1.md) | Jun 19, 2026 | | Linux | python313-documentation opensuse-leap 16.0 | 3.13.14-160000.1.1 | [OPENSUSE-SU-2026:21459-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21459-1.md) | Jul 28, 2026 | | Linux | python313-nogil opensuse-leap 16.0 | 3.13.14-160000.1.1 | [OPENSUSE-SU-2026:21459-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21459-1.md) | Jul 28, 2026 | | Linux | python313-nogil-nogil-core opensuse-leap 16.0 | 3.13.14-160000.1.1 | [OPENSUSE-SU-2026:21459-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21459-1.md) | Jul 28, 2026 | ## No fix yet | Platform | Product | Status | |---|---|---| | Windows apps | Python 2 | no-fix | | Windows apps | Python 3.10 | no-fix | | Windows apps | Python 3.11 | no-fix | | Windows apps | Python 3.12 | no-fix | | Windows apps | Python 3.5 | no-fix | | Windows apps | Python 3.6 | no-fix | | Windows apps | Python 3.7 | no-fix | | Windows apps | Python 3.8 | no-fix | | Windows apps | Python 3.9 | no-fix | --- Data as of 2026-11-08T00:53:09Z UTC. 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