CVE-2023-36461

Mastodon vulnerable to Denial of Service through slow HTTP responses

Description

Mastodon is a free, open-source social network server based on ActivityPub. When performing outgoing HTTP queries, Mastodon sets a timeout on individual read operations. Prior to versions 3.5.9, 4.0.5, and 4.1.3, a malicious server can indefinitely extend the duration of the response through slowloris-type attacks. This vulnerability can be used to keep all Mastodon workers busy for an extended duration of time, leading to the server becoming unresponsive. Versions 3.5.9, 4.0.5, and 4.1.3 contain a patch for this issue.

Category

7.5
CVSS
Severity: High
CVSS 3.1 •
EPSS 0.16%
Third-Party Advisory github.com Third-Party Advisory github.com Third-Party Advisory github.com Third-Party Advisory github.com Third-Party Advisory github.com
Affected: mastodon mastodon
Published at:
Updated at:

References

Link Tags
https://github.com/mastodon/mastodon/security/advisories/GHSA-9pxv-6qvf-pjwc third party advisory
https://github.com/mastodon/mastodon/commit/c5929798bf7e56cc2c79b15bed0c4692ded3dcb6 third party advisory patch
https://github.com/mastodon/mastodon/releases/tag/v3.5.9 third party advisory
https://github.com/mastodon/mastodon/releases/tag/v4.0.5 third party advisory
https://github.com/mastodon/mastodon/releases/tag/v4.1.3 third party advisory
http://www.openwall.com/lists/oss-security/2023/07/06/7 mailing list

Frequently Asked Questions

What is the severity of CVE-2023-36461?
CVE-2023-36461 has been scored as a high severity vulnerability.
How to fix CVE-2023-36461?
To fix CVE-2023-36461, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2023-36461 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2023-36461 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2023-36461?
CVE-2023-36461 affects mastodon mastodon.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.