CVE-2025-12781 describes a data integrity vulnerability in the Python "base64" module, specifically affecting the b64decode(), standard_b64decode(), and urlsafe_b64decode() functions. These functions incorrectly accept '+' and '/' characters even when an alternative base64 alphabet is specified, potentially leading to data integrity issues if an application relies on a strict alternative alphabet. Rated 5.3 MEDIUM (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N), the vulnerability is network-exploitable with low attack complexity, but its impact is limited to data integrity (I:L). There is currently no evidence of active exploitation, public exploit code, or inclusion in the KEV catalog, though it has garnered some community discussion and media coverage.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
>= 0, < 3.13.10CPE match | cpe:2.3:a:python:python:*:*:*:*:*:*:*:* | ||
>= 3.14.0, < 3.14.1CPE match | cpe:2.3:a:python:python:*:*:*:*:*:*:*:* | ||
< 3.13.10CPE matchmatch criteria | cpe:2.3:a:python:python:*:*:*:*:*:*:*:* | ||
3.15.0CPE matchmatch criteria | cpe:2.3:a:python:python:3.15.0:alpha1:*:*:*:*:*:* |
CVSS version used by this source: 4.0
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.4 GitHub mentions.
The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.