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High

Undertow Denial of Service vulnerability

  • Disclosed: 08.07.2024
  • Updated: 11.10.2026 12:21

A vulnerability was found in Undertow, where the chunked response hangs after the body was flushed. The response headers and body were sent but the client would continue waiting as Undertow does not send the expected 0\r\n termination of the chunked response. This results in uncontrolled resource consumption, leaving the server side to a denial of service attack. This happens only with Java 17 TLSv1.3 scenarios.

Affected software

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PlatformPackageVulnerable versionsFixed in
Java / Kotlin (Maven) io.undertow:undertow-core >= 2.3.0.Alpha1, < 2.3.15.Final, < 2.2.34.Final 2.3.15.Final, 2.2.34.Final

References

CVSS score 7.5/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE)
CWE-674
Platform
Java / Kotlin (Maven)
Package
io.undertow:undertow-core
Disclosed
08.07.2024
Updated
11.10.2026 12:21

Sources and licenses

OSV / GitHub Advisory Database - GHSA-xpp6-8r3j-ww43 - CC BY 4.0

Vulnerability history: io.undertow:undertow-core

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.

All (39) in the archive
Total entries
39
First → latest
10.2018 03.2026
Without a fix
1
Exploited in attacks
0

Severity breakdown

  • Critical 4
  • High 19
  • Medium 16

Disclosures per year

Severity:
  1. Undertow Servlets Vulnerable to Remote DoS via OutOfMemoryError when Passed Large Parameter Names
    High · 7.5 CVE-2024-4027 < 2.2.39.Final, >= 2.4.0.Alpha1, < 2.4.0.Beta1, >= 2.3.0.Alpha1, < 2.3.21.Final 2.2.39.Final, 2.4.0.Beta1, 2.3.21.Final
  2. Undertow HTTP server core doesn't properly validate the Host header in incoming HTTP requests
    Critical · 9.6 CVE-2025-12543 >= 2.3.0.Alpha1, < 2.3.21.Final, < 2.2.39.Final, = 2.4.0.Alpha1 2.3.21.Final, 2.2.39.Final
  3. Undertow OutOfMemory when parsing form data encoding with application/x-www-form-urlencoded
    High · 7.5 CVE-2024-3884 < 2.2.39.Final, >= 2.4.0.Alpha1, < 2.4.0.Beta1, >= 2.3.0.Alpha1, < 2.3.21.Final 2.2.39.Final, 2.4.0.Beta1, 2.3.21.Final
  4. Undertow MadeYouReset HTTP/2 DDoS Vulnerability
    High · 7.5 CVE-2025-9784 < 2.2.38.Final, >= 2.3.0.Alpha1, < 2.3.20.Final 2.2.38.Final, 2.3.20.Final
  5. Undertow incorrectly parses cookies
    High · 7.4 CVE-2023-4639 >= 2.3.0.Alpha1, < 2.3.11.Final, < 2.2.30.Final 2.3.11.Final, 2.2.30.Final
  6. Undertow vulnerable to Race Condition
    High · 7.5 CVE-2024-7885 < 2.2.36.Final, >= 2.3.0.Alpha1, < 2.3.17.Final 2.2.36.Final, 2.3.17.Final
  7. Undertow Denial of Service vulnerability this entry
    High · 7.5 CVE-2024-5971 >= 2.3.0.Alpha1, < 2.3.15.Final, < 2.2.34.Final 2.3.15.Final, 2.2.34.Final
  8. Undertow's url-encoded request path information can be broken on ajp-listener
    High · 7.5 CVE-2024-6162 >= 2.3.0.Alpha1, < 2.3.14.Final, < 2.2.33.Final 2.3.14.Final, 2.2.33.Final
  9. Undertow Uncontrolled Resource Consumption Vulnerability
    High · 7.5 CVE-2024-1635 >= 2.3.0.Final, < 2.3.12.Final, < 2.2.31.Final 2.3.12.Final, 2.2.31.Final
  10. Undertow denial of service vulnerability
    High · 7.5 CVE-2023-1108 >= 2.3.0, < 2.3.5.Final, < 2.2.24.Final 2.3.5.Final, 2.2.24.Final
  11. Undertow client not checking server identity presented by server certificate in https connections
    Critical · 9.8 CVE-2022-4492 >= 2.3.0, < 2.3.5.Final, < 2.2.24.Final 2.3.5.Final, 2.2.24.Final
  12. Undertow vulnerable to Dos via Large AJP request
    High · 7.5 CVE-2022-2053 < 2.2.19.Final, >= 2.3.0.Alpha1, < 2.3.0.Alpha2 2.2.19.Final, 2.3.0.Alpha2
  13. Undertow vulnerable to Denial of Service (DoS) attacks
    High · 7.5 CVE-2021-3859 < 2.2.15 2.2.15
  14. Undertow vulnerable to memory exhaustion due to buffer leak
    High · 7.5 CVE-2021-3690 < 2.0.40, >= 2.2.0, < 2.2.10 2.0.40, 2.2.10
  15. Undertow Uncontrolled Resource Consumption
    High · 7.5 CVE-2021-3629 < 2.0.40.Final, >= 2.1.0, < 2.2.11.Final 2.0.40.Final, 2.2.11.Final
  16. Improper Authorization in Undertoe
    High · 8.6 CVE-2020-1745 < 2.0.30 2.0.30
  17. Improper Input Validation in Undertow
    High · 8.1 CVE-2020-1757 < 2.1.0 2.1.0
  18. Undertow vulnerable to Uncontrolled Resource Consumption
    High · 7.5 CVE-2019-14888 < 2.0.29.Final 2.0.29.Final
  19. Undertow Request Smuggling vulnerability
    High · 7.5 CVE-2017-12165 < 1.3.31, >= 1.4.0, < 1.4.17, >= 2.0.0.Alpha1, < 2.0.0.Beta1 1.3.31, 1.4.17, 2.0.0.Beta1
  20. Denial of service in Undertow
    High · 7.5 CVE-2020-27782 >= 2.1.0, < 2.1.5, < 2.0.33 2.1.5, 2.0.33
  21. Allocation of Resources Without Limits or Throttling in Undertow
    High · 7.5 CVE-2020-10705 < 2.1.1.Final 2.1.1.Final
  22. Potential to access user credentials from the log files when debug logging enabled
    Critical · 9.8 CVE-2019-10212 < 2.0.20 2.0.20
  23. Credential exposure through log files in Undertow
    Critical · 9.8 CVE-2019-3888 < 2.0.21 2.0.21

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