Apache Tomcat Race Condition vulnerability
The simplified implementation of blocking reads and writes introduced in Tomcat 10 and back-ported to Tomcat 9.0.47 onwards exposed a long standing (but extremely hard to trigger) concurrency bug in Apache Tomcat 10.1.0 to 10.1.0-M12, 10.0.0-M1 to 10.0.18, 9.0.0-M1 to 9.0.60 and 8.5.0 to 8.5.77 that could cause client connections to share an Http11Processor instance resulting in responses, or part responses, to be received by the wrong client.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Java / Kotlin (Maven) | org.apache.tomcat:tomcat | >= 8.5.0, < 8.5.78, >= 9.0.0-M1, < 9.0.62, >= 10.0.0-M1, < 10.0.20, >= 10.1.0-M1, < 10.1.0-M14 | 8.5.78, 9.0.62, 10.0.20, 10.1.0-M14 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2021-43980
- https://github.com/apache/tomcat/commit/170e0f792bd18ff031677890ba2fe50eb7a376c1
- https://github.com/apache/tomcat/commit/17f177eeb7df5938f67ef9ea580411b120195f13
- https://github.com/apache/tomcat/commit/4a00b0c0890538b9d3107eef8f2e0afadd119beb
- https://github.com/apache/tomcat/commit/9651b83a1d04583791525e5f0c4c9089f678d9fc
- https://github.com/apache/tomcat
- https://lists.apache.org/thread/3jjqbsp6j88b198x5rmg99b1qr8ht3g3
- https://lists.debian.org/debian-lts-announce/2022/10/msg00029.html
- https://tomcat.apache.org/security-10.html
- https://tomcat.apache.org/security-8.html
- https://tomcat.apache.org/security-9.html
- https://www.debian.org/security/2022/dsa-5265
- http://www.openwall.com/lists/oss-security/2022/09/28/1
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N- Weakness (CWE)
CWE-362- Platform
- Java / Kotlin (Maven)
- Package
org.apache.tomcat:tomcat- Disclosed
- 29.09.2022
- Updated
- 11.10.2026 12:21
Sources and licenses
OSV / GitHub Advisory Database - GHSA-jx7c-7mj5-9438 - CC BY 4.0
Vulnerability history: org.apache.tomcat:tomcat
All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 162
- First → latest
- 12.2018 08.2026
- Without a fix
- 20
- Exploited in attacks
- 1
Severity breakdown
- Critical 8
- High 40
- Medium 102
- Low 12
Disclosures per year
- 2018: 1
- 2019: 1
- 2020: 2
- 2021: 5
- 2022: 125
- 2023: 3
- 2024: 2
- 2025: 4
- 2026: 19
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Apache Tomcat Race Condition vulnerability this entry
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