csirt@kutim:~/threat-intel/cve/CVE-2025-12781

Katalog CVE

CVSS 5.3 · Medium EPSS 0,57%

Kerentanan Incorrect Type Conversion or Cast pada python. Skor CVSS 3.1 5.3 (Medium) menurut NVD.

Deskripsi (NVD)

When passing data to the b64decode(), standard_b64decode(), and urlsafe_b64decode() functions in the "base64" module the characters "+/" will always be accepted, regardless of the value of "altchars" parameter, typically used to establish an "alternative base64 alphabet" such as the URL safe alphabet. This behavior matches what is recommended in earlier base64 RFCs, but newer RFCs now recommend either dropping characters outside the specified base64 alphabet or raising an error. The old behavior has the possibility of causing data integrity issues. This behavior can only be insecure if your application uses an alternate base64 alphabet (without "+/"). If your application does not use the "altchars" parameter or the urlsafe_b64decode() function, then your application does not use an alternative base64 alphabet. The attached patches DOES NOT make the base64-decode behavior raise an error, as this would be a change in behavior and break existing programs. Instead, the patch deprecates the behavior which will be replaced with the newly recommended behavior in a future version of Python. Users are recommended to mitigate by verifying user-controlled inputs match the base64 alphabet they are expecting or verify that their application would not be affected if the b64decode() functions accepted "+" or "/" outside of altchars.

Rincian

Terbit di NVD
21 Januari 2026
Terakhir diubah
17 Juni 2026
Status NVD
Analyzed
CVSS 3.1
5.3 (Medium), sumber NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N · uraikan di kalkulator
Jenis kelemahan (CWE)
CWE-704: Incorrect Type Conversion or Cast
EPSS (30 hari)
0,57% peluang dieksploitasi; lebih tinggi dari 45,6% CVE lain

Produk dan versi terdampak

VendorProdukVersi terdampak
python python Semua versi sebelum 3.13.10
python python Versi 3.14.0 hingga sebelum 3.14.1
python python Versi 3.15.0 alpha1

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

Sumber: NVD · CVE.org · EPSS. Halaman ini disusun otomatis dari data tersebut; pembaruan terakhir 5 Okt 2026, 20:11 WITA. Kalau sistem di Perangkat Daerah memakai produk ini dan butuh bantuan, laporkan lewat kanal pelaporan.