What’s Vulnerable › Vulnerabilities

CVE-2018-21018

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2019-09-22 · updated 2026-06-17
• Weakness: CWE-613

Description

Mastodon before 2.6.3 mishandles timeouts of incompletely established sessions.

Affected products

• mastodon: before 2.6.3 — fixed in 2.6.3

How to fix

Upgrade to a fixed version: mastodon 2.6.3. Check the vendor advisory for mitigations.

References

• https://github.com/tootsuite/mastodon/pull/9329
• https://github.com/tootsuite/mastodon/pull/9381
• https://github.com/tootsuite/mastodon/releases/tag/v2.6.2
• https://github.com/tootsuite/mastodon/releases/tag/v2.6.3
• https://github.com/tootsuite/mastodon/pull/9329
• https://github.com/tootsuite/mastodon/pull/9381
• https://github.com/tootsuite/mastodon/releases/tag/v2.6.2
• https://github.com/tootsuite/mastodon/releases/tag/v2.6.3

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