Fluid Attacks Database

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.

Mitigation

Update Impact

Minimal update. May introduce new vulnerabilities or breaking changes.

Ecosystem	Component	Affected version	Patched versions
rpm rhel10	python3.14	-	-
rpm rhel9	python3.14	-	-
debian 12	python3.11	=3.11.2-6 \|\| =3.11.2-6+deb12u1 \|\| =3.11.2-6+deb12u2 \|\| =3.11.2-6+deb12u3 \|\| =3.11.2-6+deb12u4 \|\| =3.11.2-6+deb12u5 \|\| =3.11.2-6+deb12u6 \|\| =3.11.2-6+deb12u7 \|\| =3.11.2-6+deb12u8 \|\| =3.11.3-1 \|\| =3.11.3-2 \|\| =3.11.4-1 \|\| =3.11.5-1 \|\| =3.11.5-2 \|\| =3.11.5-3 \|\| =3.11.6-1 \|\| =3.11.6-2 \|\| =3.11.6-3 \|\| =3.11.6-3~hurd.2 \|\| =3.11.7-1 \|\| =3.11.7-2 \|\| =3.11.8-1 \|\| =3.11.8-1.1~exp1 \|\| =3.11.8-1.1~exp2 \|\| =3.11.8-2 \|\| =3.11.8-3 \|\| =3.11.8-3+hurd.1 \|\| =3.11.9-1	-
debian 13	python3.13	=3.13.5-2 \|\| =3.13.5-2+deb13u1 \|\| >=0 <3.13.5-2+deb13u2	3.13.5-2+deb13u2
debian 14	python3.13	=3.13.11-1 \|\| =3.13.12-1 \|\| =3.13.5-2 \|\| =3.13.6-1 \|\| =3.13.7-1 \|\| =3.13.8-1 \|\| =3.13.9-1 \|\| >=0 <3.13.14-1	3.13.14-1
debian 14	python3.14	=3.14.0-1 \|\| =3.14.0-2 \|\| =3.14.0-3 \|\| =3.14.0-4 \|\| =3.14.0-5 \|\| =3.14.0~a7-1 \|\| =3.14.0~b1-1 \|\| =3.14.0~b2-1 \|\| =3.14.0~b3-1 \|\| =3.14.0~b4-1 \|\| =3.14.0~rc1-1 \|\| =3.14.0~rc2-1 \|\| =3.14.0~rc3-1 \|\| =3.14.2-1 \|\| =3.14.3-1 \|\| =3.14.3-2 \|\| =3.14.3-3 \|\| =3.14.3-4 \|\| =3.14.3-5 \|\| >=0 <3.14.4-1	3.14.4-1
pypi	python	>=0 <3.13.13 \|\| >=3.14.0 <3.14.4 \|\| >=3.15.0a1 <3.15.0a8	3.13.13, 3.14.4, 3.15.0a8

Aliases

1. CVE-2026-34462. NVD-2026-34463. OSV-2026-34464. OSV-DEBIAN-2026-34465. GCVE-2026-34466. SECURITY-TRACKER-CVE-2026-34467. https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/3xxx/CVE-2026-3446.json8. mail.python.org

References

1. https://github.com/python/cpython/issues/1452642. https://github.com/python/cpython/commit/1f9958f909c1b41a4ffc0b613ef8ec8fa5e7c4743. https://github.com/python/cpython/commit/4561f6418a691b3e89aef0901f53fe0dfb7f7c0e4. https://github.com/python/cpython/commit/e31c55121620189a0d1a07b689762d8ca9c1b7fa5. https://github.com/python/cpython/pull/145267

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