CVE-2026-54915

MEDIUM
Published Sep 21, 2026 Modified Sep 24, 2026 CWE-601

Description

Tautulli is a Python based monitoring and tracking tool for Plex Media Server. Prior to 2.17.2, the unauthenticated /auth/redirect endpoint in plexpy/webauth.py removes forward slashes from the user-controlled redirect_uri parameter but leaves tab, line-feed, and carriage-return characters intact. With the default root HTTP_ROOT configuration, CherryPy HTTPRedirect passes the resulting value to urllib.parse.urljoin, which can resolve the whitespace-bearing path to an attacker-controlled external origin. A user who follows a crafted link can therefore be redirected outside Tautulli for phishing or post-login redirect-flow abuse, while custom non-root HTTP_ROOT configurations are not affected by this bypass. This issue is fixed in version 2.17.2.

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CVSS v3.1 Score

5.4
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

EPSS — Exploit Prediction

0.0026
Probability of exploitation
0.16%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-601 CWE-601

References

Frequently Asked Questions

What is CVE-2026-54915? +
Tautulli is a Python based monitoring and tracking tool for Plex Media Server. Prior to 2.17.2, the unauthenticated /auth/redirect endpoint in plexpy/webauth.py removes forward slashes from the user-controlled redirect_uri parameter but leaves tab, line-feed, and carriage-return characters intact. With the default root HTTP_ROOT configuration, CherryPy HTTPRedirect passes the resulting value to urllib.parse.urljoin, which can resolve the whitespace-bearing path to an attacker-controlled external origin. A user who follows a crafted link can therefore be redirected outside Tautulli for phishing or post-login redirect-flow abuse, while custom non-root HTTP_ROOT configurations are not affected by this bypass. This issue is fixed in version 2.17.2. It has a CVSS v3.1 base score of 5.4 (MEDIUM).
How severe is CVE-2026-54915? +
CVE-2026-54915 has a CVSS v3.1 score of 5.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0026, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-54915? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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