Vulnerability · Published Apr 24, 2026 · Assigned by GitHub_M
CVE-2026-41426pretalx: Email injection via unescaped user-controlled placeholders in pretalx mail templates
Medium 6.1
In plain English
A medium-severity cross-site scripting in pretalx from pretalx. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
pretalx is a conference planning tool. Prior to 2026.1.0, an unauthenticated attacker can send arbitrary HTML-rendered emails from a pretalx instance's configured sender address by embedding malformed HTML or markdown link syntax in a user-controlled template placeholder such as the account display name. The most direct vector is the password-reset flow: the attacker registers an account with a malicious name, enters the victim's email address, and triggers a password reset. The resulting email is delivered from the event's legitimate sender address and passes SPF/DKIM/DMARC validation, making it a ready-made phishing vector. This vulnerability is fixed in 2026.1.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | pretalx | 2026.1.0 | GHSA-jm8c-9f3j-4378 |
| PyPI | pretalx | 2026.1.0 | PYSEC-2026-109 |
Affected products (as reported)
Weakness: CWE-79, CWE-116 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
References
- https://github.com/pretalx/pretalx/security/advisories/GHSA-jm8c-9f3j-4378 x_refsource_CONFIRM