Presence of non-blacklisted URL bypasses all other filters

published 2021-11-05 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-28298

cvss: 4.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.8%; EPSS 0.8% chance of exploitation in 30 days, percentile 55%
public exploits: 0; none known

Python discord bot is the community bot for the Python Discord community. In affected versions when a non-blacklisted URL and an otherwise triggering filter token is included in the same message the token filter does not trigger. This means that by including any non-blacklisted URL moderation filters can be bypassed. This issue has been resolved in commit 67390298852513d13e0213870e50fb3cff1424e0

Patch / fix

fixed in 1 links 2

pythondiscord bot 67390298852513d13e0213870e50fb3cff1424e0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-41250 updated 2025-11-21 cvss 4.3

python-discord: by including any non-blacklisted URL moderation filters can be bypassed

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.76% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
NVD	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
NVD	2.0	4.0	AV:N/AC:L/Au:S/C:N/I:P/A:N

Affected products

python-discord bot

Classification

Weakness

CWE-20 Improper Input Validation

References

github.com /python-discord/bot/commit/67390298852513d13e0213870e50fb3cff1424e0
patch, third-party-advisory
github.com /python-discord/bot/security/advisories/GHSA-j8c3-8x46-8pp6
patch, third-party-advisory

Sources

CVE List CVE-2021-41250
NVD CVE-2021-41250

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary