CVE-2026-3446

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Source
https://cve.org/CVERecord?id=CVE-2026-3446
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-3446.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-3446
Aliases
Downstream
BELL (1)
CGA (8)
DEBIAN (1)
ECHO (1)
MGASA (1)
MINI (5)
openSUSE (7)
RHSA (5)
ROOT (2)
SUSE (21)
UBUNTU (1)
Related
openSUSE (7)
SUSE (20)
Published
2026-04-10T18:17:35Z
Modified
2026-10-20T10:56:45Z
Severity
  • 6.0 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N CVSS Calculator
Summary
Base64 decoding stops at first padded quad by default
Details

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.

Database specific 
{
    "cna_assigner": "PSF",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/3xxx/CVE-2026-3446.json"
}
References

Affected packages

Git / github.com/python/cpython

Affected ranges

Type
GIT
Repo
https://github.com/python/cpython
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
01104ce1beb3135c2e0c01ec835b994c1f55a1c0
Introduced
ebf955df7a89ed0c7968f79faec1de49f61ed7cb
Fixed
23116f998f6789d8c2fbe5ed5b8146854c8c2a4f
Introduced
f31a89bb901067dd105b00cfa90523cf7ffdbbdd
Fixed
55ea59e7dc35e1363b203ae4dd9cfc3a0ac0a844
Fixed
1f9958f909c1b41a4ffc0b613ef8ec8fa5e7c474
Fixed
4561f6418a691b3e89aef0901f53fe0dfb7f7c0e
Fixed
e31c55121620189a0d1a07b689762d8ca9c1b7fa
Database specific
Show details 
{
    "extracted_events": [
        {
            "range": [
                {
                    "introduced": "0"
                },
                {
                    "fixed": "3.13.13"
                }
            ],
            "source": "AFFECTED_FIELD",
            "strategy": "StandardRange"
        },
        {
            "range": [
                {
                    "introduced": "3.14.0"
                },
                {
                    "fixed": "3.14.4"
                }
            ],
            "source": "AFFECTED_FIELD",
            "strategy": "StandardRange"
        },
        {
            "range": [
                {
                    "introduced": "3.15.0a1"
                },
                {
                    "fixed": "3.15.0a8"
                }
            ],
            "source": "AFFECTED_FIELD",
            "strategy": "StandardRange"
        },
        {
            "range": [
                {
                    "fixed": "1f9958f909c1b41a4ffc0b613ef8ec8fa5e7c474"
                }
            ],
            "source": "REFERENCES_COMMIT"
        },
        {
            "range": [
                {
                    "fixed": "4561f6418a691b3e89aef0901f53fe0dfb7f7c0e"
                }
            ],
            "source": "REFERENCES_COMMIT"
        },
        {
            "range": [
                {
                    "fixed": "e31c55121620189a0d1a07b689762d8ca9c1b7fa"
                }
            ],
            "source": "REFERENCES_COMMIT"
        }
    ]
}

Affected versions

v0.*
v0.9.8
v0.9.9
v1.*
v1.0.1
v1.0.2
v1.1
v1.1.1
v1.2
v1.2b1
v1.2b2
v1.2b3
v1.2b4
v1.3
v1.3b1
v1.4
v1.4b1
v1.4b2
v1.4b3
v1.5
v1.5.1
v1.5.2
v1.5.2a1
v1.5.2a2
v1.5.2b1
v1.5.2b2
v1.5.2c1
v1.5a1
v1.5a2
v1.5a3
v1.5a4
v1.5b1
v1.5b2
v1.6a1
v1.6a2
v2.*
v2.0
v2.0b1
v2.0b2
v2.0c1
v2.1
v2.1a1
v2.1a2
v2.1b1
v2.1b2
v2.1c1
v2.1c2
v2.2a3
v2.3c1
v2.3c2
v2.4
v2.4a1
v2.4a2
v2.4a3
v2.4b1
v2.4b2
v2.4c1
v3.*
v3.0a1
v3.0a2
v3.0a3
v3.0a4
v3.0a5
v3.0b1
v3.0b2
v3.0b3
v3.0rc1
v3.0rc2
v3.0rc3
v3.1
v3.10.0a1
v3.10.0a7
v3.11.0a3
v3.11.0a4
v3.11.0a5
v3.11.0a6
v3.11.0a7
v3.11.0b1
v3.12.0a1
v3.12.0a2
v3.12.0a3
v3.12.0a4
v3.12.0a5
v3.12.0a6
v3.12.0a7
v3.12.0b1
v3.13.0
v3.13.0a1
v3.13.0a2
v3.13.0a3
v3.13.0a4
v3.13.0a5
v3.13.0a6
v3.13.0b1
v3.13.0b2
v3.13.0b3
v3.13.0b4
v3.13.0rc1
v3.13.0rc2
v3.13.0rc3
v3.13.1
v3.13.10
v3.13.11
v3.13.12
v3.13.2
v3.13.3
v3.13.4
v3.13.5
v3.13.6
v3.13.7
v3.13.8
v3.14.0
v3.14.0a1
v3.14.0a2
v3.14.0a3
v3.14.0a4
v3.14.0a5
v3.14.0a6
v3.14.0a7
v3.14.0b1
v3.14.1
v3.14.2
v3.14.3
v3.15.0a1
v3.15.0a2
v3.15.0a3
v3.15.0a4
v3.15.0a5
v3.15.0a6
v3.15.0a7
v3.1a1
v3.1a2
v3.1b1
v3.1rc1
v3.1rc2
v3.2a1
v3.2a2
v3.2a3
v3.2a4
v3.2b1
v3.2b2
v3.2rc1
v3.2rc2
v3.2rc3
v3.3.0a2
v3.3.0a3
v3.3.0a4
v3.3.0b1
v3.3.0b2
v3.3.0rc1
v3.3.0rc2
v3.3.0rc3
v3.4.0a1
v3.4.0a2
v3.4.0a3
v3.4.0a4
v3.4.0b1
v3.4.0b2
v3.4.0b3
v3.5.0a1
v3.5.0a2
v3.5.0a3
v3.5.0a4
v3.5.0b1
v3.6.0a3
v3.6.0b1
v3.7.0a2
v3.9.0a2

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-3446.json"
vanir_signatures 
[
    {
        "deprecated": false,
        "digest": {
            "function_hash": "103369807178508843048769308770419387734",
            "length": 2230
        },
        "id": "CVE-2026-3446-0b934374",
        "signature_type": "Function",
        "signature_version": "v1",
        "source": "https://github.com/python/cpython/commit/1f9958f909c1b41a4ffc0b613ef8ec8fa5e7c474",
        "target": {
            "file": "Modules/binascii.c",
            "function": "binascii_a2b_base64_impl"
        }
    },
    {
        "deprecated": false,
        "digest": {
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                "13024832950729763097226277911512554200",
                "8969369628337930508571551292381739191"
            ],
            "threshold": 0.9
        },
        "id": "CVE-2026-3446-6254466f",
        "signature_type": "Line",
        "signature_version": "v1",
        "source": "https://github.com/python/cpython/commit/4561f6418a691b3e89aef0901f53fe0dfb7f7c0e",
        "target": {
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        }
    },
    {
        "deprecated": false,
        "digest": {
            "function_hash": "103369807178508843048769308770419387734",
            "length": 2230
        },
        "id": "CVE-2026-3446-7ba7bbf9",
        "signature_type": "Function",
        "signature_version": "v1",
        "source": "https://github.com/python/cpython/commit/e31c55121620189a0d1a07b689762d8ca9c1b7fa",
        "target": {
            "file": "Modules/binascii.c",
            "function": "binascii_a2b_base64_impl"
        }
    },
    {
        "deprecated": false,
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        "id": "CVE-2026-3446-8fa1a7b2",
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        "digest": {
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            ],
            "threshold": 0.9
        },
        "id": "CVE-2026-3446-e6a88939",
        "signature_type": "Line",
        "signature_version": "v1",
        "source": "https://github.com/python/cpython/commit/e31c55121620189a0d1a07b689762d8ca9c1b7fa",
        "target": {
            "file": "Modules/binascii.c"
        }
    }
]
vanir_signatures_modified 
"2026-10-16T07:22:30Z"