Apache Tomcat: Request header mix-up between HTTP/2 streams

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2020-17527
StatePUBLISHED
Assignerapache
Source PriorityCVE Program / NVD first with legacy fallback
Published2020-12-03 19:15:12 UTC
Updated2026-10-08 22:16:57 UTC
DescriptionWhile investigating bug 64830 it was discovered that Apache Tomcat 10.0.0-M1 to 10.0.0-M9, 9.0.0-M1 to 9.0.39 and 8.5.0 to 8.5.59 could re-use an HTTP request header value from the previous stream received on an HTTP/2 connection for the request associated with the subsequent stream. While this would most likely lead to an error and the closure of the HTTP/2 connection, it is possible that information could leak between requests.

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS: 0.246220000 probability, percentile 0.978420000 (date 2026-10-11)

Problem Types: CWE-200 | CWE-200 CWE-200 Information Exposure

VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
2.0[email protected]Primary5AV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS v2.0 Breakdown

Access Vector
Network
Access Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
None
Availability
None

AV:N/AC:L/Au:N/C:P/I:N/A:N

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Apache Tomcat 10.0.0 milestone1 All All
Application Apache Tomcat 10.0.0 milestone2 All All
Application Apache Tomcat 10.0.0 milestone3 All All
Application Apache Tomcat 10.0.0 milestone4 All All
Application Apache Tomcat 10.0.0 milestone5 All All
Application Apache Tomcat 10.0.0 milestone6 All All
Application Apache Tomcat 10.0.0 milestone7 All All
Application Apache Tomcat 10.0.0 milestone8 All All
Application Apache Tomcat 10.0.0 milestone9 All All
Application Apache Tomcat 9.0.0 milestone10 All All
Application Apache Tomcat 9.0.0 milestone11 All All
Application Apache Tomcat 9.0.0 milestone12 All All
Application Apache Tomcat 9.0.0 milestone13 All All
Application Apache Tomcat 9.0.0 milestone14 All All
Application Apache Tomcat 9.0.0 milestone15 All All
Application Apache Tomcat 9.0.0 milestone16 All All
Application Apache Tomcat 9.0.0 milestone17 All All
Application Apache Tomcat 9.0.0 milestone18 All All
Application Apache Tomcat 9.0.0 milestone19 All All
Application Apache Tomcat 9.0.0 milestone20 All All
Application Apache Tomcat 9.0.0 milestone21 All All
Application Apache Tomcat 9.0.0 milestone22 All All
Application Apache Tomcat 9.0.0 milestone23 All All
Application Apache Tomcat 9.0.0 milestone24 All All
Application Apache Tomcat 9.0.0 milestone25 All All
Application Apache Tomcat 9.0.0 milestone26 All All
Application Apache Tomcat 9.0.0 milestone27 All All
Application Apache Tomcat 9.0.0 milestone5 All All
Application Apache Tomcat 9.0.0 milestone6 All All
Application Apache Tomcat 9.0.0 milestone7 All All
Application Apache Tomcat 9.0.0 milestone8 All All
Application Apache Tomcat 9.0.0 milestone9 All All
Application Apache Tomcat 9.0.35-3.39.1 All All All
Application Apache Tomcat 9.0.35-3.57.3 All All All
Application Apache Tomcat 9.0.36 All All All
Application Apache Tomcat 9.0.37 All All All
Application Apache Tomcat 9.0.38 All All All
Application Apache Tomcat 9.0.39 All All All
Application Apache Tomcat All All All All
Application Apache Tomcat All All All All
Operating System Debian Debian Linux 10.0 All All All
Operating System Debian Debian Linux 9.0 All All All
Application Netapp Element Plug-in - All All All
Application Netapp Oncommand System Manager All All All All
Application Oracle Blockchain Platform All All All All
Application Oracle Communications Cloud Native Core Binding Support Function 1.10.0 All All All
Application Oracle Communications Cloud Native Core Policy 1.14.0 All All All
Application Oracle Communications Instant Messaging Server 10.0.1.5.0 All All All
Application Oracle Instantis Enterprisetrack 17.1 All All All
Application Oracle Instantis Enterprisetrack 17.2 All All All
Application Oracle Instantis Enterprisetrack 17.3 All All All
Application Oracle Mysql Enterprise Monitor All All All All
Application Oracle Sd-wan Edge 9.0 All All All
Application Oracle Workload Manager 18c All All All
Application Oracle Workload Manager 19c All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Apache Software Foundation Apache Tomcat affected Apache Tomcat 10 10.0.0-M1 to 10.0.0-M9 Not specified
CNA Apache Software Foundation Apache Tomcat affected Apache Tomcat 9 9.0.0-M1 to 9.0.39 Not specified
CNA Apache Software Foundation Apache Tomcat affected Apache Tomcat 8.5 8.5.0 to 8.5.59 Not specified

References

ReferenceSourceLinkTags
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
lists.apache.org/thread.html/rca833c6d42b7b9ce1563488c0929f29fcc95947d86e5e740... af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Oracle Critical Patch Update Advisory - April 2022 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Oracle Critical Patch Update Advisory - July 2021 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org Mailing List, Vendor Advisory
Oracle Critical Patch Update Advisory - January 2022 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
Oracle Critical Patch Update Advisory - April 2021 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Apache Tomcat: Information disclosure (GLSA 202012-23) — Gentoo security af854a3a-2127-422b-91ae-364da2661108 security.gentoo.org Third Party Advisory
CVE-2020-17527 Apache Tomcat Vulnerability in NetApp Products | NetApp Product Security af854a3a-2127-422b-91ae-364da2661108 security.netapp.com Third Party Advisory
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
oss-security - [SECURITY] CVE-2020-17527 Apache Tomcat HTTP/2 Request header mix-up af854a3a-2127-422b-91ae-364da2661108 www.openwall.com Mailing List, Third Party Advisory
Debian -- Security Information -- DSA-4835-1 tomcat9 af854a3a-2127-422b-91ae-364da2661108 www.debian.org Third Party Advisory
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
[SECURITY] [DLA 2495-1] tomcat8 security update af854a3a-2127-422b-91ae-364da2661108 lists.debian.org Mailing List, Third Party Advisory
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Legacy QID Mappings

  • 198724 Ubuntu Security Notification for Tomcat Vulnerabilities (USN-5360-1)
  • 20215 Oracle Database 19c Critical Patch Update - April 2021
  • 20216 Oracle Database 18c Critical Patch Update - April 2021
  • 20275 Oracle Database 18c Critical OJVM Patch Update - April 2021
  • 20278 Oracle Database 19c Critical OJVM Patch Update - April 2021
  • 239735 Red Hat Update for red hat jboss web server 5.4.1 (RHSA-2021:0494)
  • 356178 Amazon Linux Security Advisory for tomcat : ALASTOMCAT8.5-2023-010
  • 750427 OpenSUSE Security Update for tomcat (openSUSE-SU-2021:0081-1)
  • 750441 OpenSUSE Security Update for tomcat (openSUSE-SU-2021:0043-1)
  • 901682 Common Base Linux Mariner (CBL-Mariner) Security Update for tomcat (7384)
  • 901917 Common Base Linux Mariner (CBL-Mariner) Security Update for tomcat (6909)

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report