Description
When responding to new h2c connection requests, Apache Tomcat versions 10.0.0-M1 to 10.0.0, 9.0.0.M1 to 9.0.41 and 8.5.0 to 8.5.61 could duplicate request headers and a limited amount of request body from one request to another meaning user A and user B could both see the results of user A's request.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Apache Software Foundation | Apache Tomcat | Apache Tomcat 10 – < 10.0.2, Apache Tomcat 9 – < 9.0.42, Apache Tomcat 8.5 – < 8.5.62 | 10.0.2 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | tomcat9 | 9.0.43-1 | — |
| Debian 13 | tomcat9 | 9.0.43-1 | — |
| Debian 12 | tomcat9 | 9.0.43-1 | — |
| Debian 10 | tomcat9 | 9.0.31-1~deb10u4 | DSA-4891-1 |
| Debian 9 | tomcat8 | 8.5.54-0+deb9u6 | DLA-2594-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | tomcat9 | 9.0.31-1ubuntu0.2 | USN-6943-1, USN-5360-1 |
| Ubuntu 18.04 LTS | tomcat9 | 9.0.16-3ubuntu0.18.04.2 | USN-5360-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 22.04 LTS | tomcat9 | 9.0.58-1ubuntu0.1+esm2 | USN-6943-1 |
| Ubuntu Pro 18.04 LTS | tomcat8 | 8.5.39-1ubuntu1~18.04.3+esm2 | USN-6943-1 |
| Ubuntu Pro 18.04 LTS | tomcat9 | 9.0.16-3ubuntu0.18.04.2+esm2 | USN-6943-1 |
| Ubuntu Pro 16.04 LTS | tomcat8 | 8.0.32-1ubuntu1.13+esm1 | USN-6943-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat JBoss Web Server 5 | jws5-ecj | 4.12.0-3.redhat_2.2.el7jws | RHSA-2021:2561 |
| Red Hat JBoss Web Server 5 | jws5-mod_cluster +1 | 1.4.3-2.Final_redhat_00002.1.el7jws | RHSA-2021:2561 |
| Red Hat JBoss Web Server 5 | jws5-tomcat +11 | 9.0.43-11.redhat_00011.1.el7jws | RHSA-2021:2561 |
| Red Hat JBoss Web Server 5 | jws5-tomcat-native | 1.2.26-3.redhat_3.el7jws | RHSA-2021:2561 |
| Red Hat JBoss Web Server 5 | jws5-tomcat-vault +1 | 1.1.8-2.Final_redhat_00003.1.el7jws | RHSA-2021:2561 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | tomcat | 9.0.36-3.24.1 | SUSE-SU-2021:1008-1 |
| SLES 15 SP1 | tomcat | 9.0.36-4.58.1 | SUSE-SU-2021:1009-1 |
| SLES 15 | tomcat | 9.0.36-3.79.1 | SUSE-SU-2021:0989-1 |
| SLES 12 SP5 | tomcat | 9.0.36-3.64.1 | SUSE-SU-2026:1058-1, SUSE-SU-2021:0988-1 |
| SLES 12 SP4 | tomcat | 9.0.36-3.64.1 | SUSE-SU-2021:0988-1 |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP1 | tomcat | 9.0.36-4.58.1 | SUSE-SU-2021:1009-1 |
| SLES for SAP 15 | tomcat | 9.0.36-3.79.1 | SUSE-SU-2021:0989-1 |
| SLES for SAP 12 SP5 | tomcat | 9.0.36-3.64.1 | SUSE-SU-2021:0988-1 |
| SLES for SAP 12 SP4 | tomcat | 9.0.36-3.64.1 | SUSE-SU-2021:0988-1 |
| SLE HPC 15 SP1 | tomcat | 9.0.36-4.58.1 | SUSE-SU-2021:1009-1 |
| SLE HPC 15 | tomcat | 9.0.36-3.79.1 | SUSE-SU-2021:0989-1 |
| SUSE OpenStack Cloud Crowbar 9 | tomcat | 9.0.36-3.64.1 | SUSE-SU-2021:0988-1 |
| SUSE OpenStack Cloud 9 | tomcat | 9.0.36-3.64.1 | SUSE-SU-2021:0988-1 |
| SUSE Manager Server 4.0 | tomcat | 9.0.36-4.58.1 | SUSE-SU-2021:1009-1 |
| SUSE Manager Retail Branch Server 4.0 | tomcat | 9.0.36-4.58.1 | SUSE-SU-2021:1009-1 |
| SUSE Manager Proxy 4.0 | tomcat | 9.0.36-4.58.1 | SUSE-SU-2021:1009-1 |
| SUSE Enterprise Storage 6 | tomcat | 9.0.36-4.58.1 | SUSE-SU-2021:1009-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | tomcat | 9.0.36-8.4 | openSUSE-SU-2024:11468-1 |
| openSUSE Tumbleweed | tomcat10 | 10.1.14-1.1 | openSUSE-SU-2024:13441-1 |
| openSUSE Leap 15.2 | tomcat | 9.0.36-lp152.2.22.1 | openSUSE-SU-2021:0496-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Maven | org.apache.tomcat:tomcat-coyote | >= 10.0.0-M1, < 10.0.2 | 10.0.2 | GHSA-j39c-c8hj-x4j3 |
| Maven | org.apache.tomcat.embed:tomcat-embed-core | >= 10.0.0-M1, < 10.0.2 | 10.0.2 | GHSA-j39c-c8hj-x4j3 |
| Maven | org.apache.tomcat.embed:tomcat-embed-core | >= 9.0.0-M1, < 9.0.43 | 9.0.43 | GHSA-j39c-c8hj-x4j3 |
| Maven | org.apache.tomcat.embed:tomcat-embed-core | >= 8.5.0, < 8.5.63 | 8.5.63 | GHSA-j39c-c8hj-x4j3 |
Advisories 17
- RHSA-2021:2561 Red Hat Security Advisory: Red Hat JBoss Web Server 5.5.0 Security release Red Hat Security Advisories (RHSA) · Oct 2, 2026
- WID-SEC-2022-0607 Red Hat FUSE: Mehrere Schwachstellen BSI CERT-Bund (WID) · Aug 9, 2026
- USN-6943-1 tomcat8, tomcat9 vulnerabilities Ubuntu Security Notices (USN) · Jun 25, 2026
- USN-5360-1 tomcat9 vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- SUSE-SU-2026:1058-1 Security update for tomcat SUSE / openSUSE Security Updates · Mar 27, 2026
- WID-SEC-2022-1099 Apache Tomcat: Mehrere Schwachstellen BSI CERT-Bund (WID) · Mar 26, 2026
- DSA-4891-1 tomcat9 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2594-1 tomcat8 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2021:1008-1 Security update for tomcat SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:0496-1 Security update for tomcat SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:11468-1 tomcat-9.0.36-8.4 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1009-1 Security update for tomcat SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:13441-1 tomcat10-10.1.14-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2022-1375 JFrog Artifactory: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 12, 2025
- SUSE-SU-2021:0988-1 Security update for tomcat SUSE / openSUSE Security Updates · May 2, 2025
- SUSE-SU-2021:0989-1 Security update for tomcat SUSE / openSUSE Security Updates · May 2, 2025
- NCSC-2025-0123 Kwetsbaarheden verholpen in Oracle Database Producten NCSC-NL (Netherlands) · Apr 16, 2025
References
- https://lists.apache.org/thread.html/r7b95bc248603360501f18c8eb03bb6001ec0ee3296205b34b07105b7%40%3Cannounce.tomcat.apache.org%3E
- [tomcat-users] 20210301 [SECURITY] CVE-2021-25122 Apache Tomcat h2c request mix-up mailing-list
- [tomcat-dev] 20210301 [SECURITY] CVE-2021-25122 Apache Tomcat h2c request mix-up mailing-list
- [tomcat-dev] 20210301 svn commit: r1887027 - in /tomcat/site/trunk: docs/security-10.html docs/security-7.html docs/security-8.html docs/security-9.html xdocs/security-10.xml xdocs/security-7.xml xdocs/security-8.xml xdocs/security-9.xml mailing-list
- [announce] 20210301 [SECURITY] CVE-2021-25122 Apache Tomcat h2c request mix-up mailing-list
- [oss-security] 20210301 CVE-2021-25122: Apache Tomcat h2c request mix-up mailing-list
- [tomcat-users] 20210305 RE: [SECURITY] CVE-2021-25122 Apache Tomcat h2c request mix-up mailing-list
- [tomcat-users] 20210305 Re: [SECURITY] CVE-2021-25122 Apache Tomcat h2c request mix-up mailing-list
- [debian-lts-announce] 20210316 [SECURITY] [DLA 2596-1] tomcat8 security update mailing-list
- DSA-4891 vendor-advisory
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://security.netapp.com/advisory/ntap-20210409-0002/
- https://www.oracle.com/security-alerts/cpuoct2021.html
- https://www.oracle.com/security-alerts/cpujan2022.html
- GLSA-202208-34 vendor-advisory