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High 7.5Published Dec 3, 2020
CVE-2020-17527Apache Tomcat: Request header mix-up between HTTP/2 streams
Updated under an hour ago ()
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It affects Apache Software Foundation Apache Tomcat and 12 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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While 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.
- CVSS
- 7.5 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Weakness (CWE)
- CWE-200
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- apache
- NVD analysis
- Modified
- Record last updated
- Oct 8, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Apache Software Foundation Apache Tomcat apache_software_foundation:apache_tomcat (from the name) | Apache Tomcat 10 10.0.0-M1 to 10.0.0-M9; Apache Tomcat 9 9.0.0-M1 to 9.0.39; Apache Tomcat 8.5 8.5.0 to 8.5.59 | CNA record |
apache tomcat apache:tomcat | from 8.5.1 through 8.5.59; from 9.0.1 through 9.0.35; 9.0.0; 9.0.0; 9.0.0; 9.0.0; 9.0.0; 9.0.0; and 32 more ranges | NVD |
netapp element_plug-in netapp:element_plug-in | all versions | NVD |
netapp oncommand_system_manager netapp:oncommand_system_manager | from 3.0.0 through 3.1.3 | NVD |
debian debian_linux debian:debian_linux | 9.0; 10.0 | NVD |
oracle blockchain_platform oracle:blockchain_platform | before 21.1.2 | NVD |
oracle communications_cloud_native_core_binding_support_function oracle:communications_cloud_native_core_binding_support_function | 1.10.0 | NVD |
oracle communications_cloud_native_core_policy oracle:communications_cloud_native_core_policy | 1.14.0 | NVD |
oracle communications_instant_messaging_server oracle:communications_instant_messaging_server | 10.0.1.5.0 | NVD |
oracle instantis_enterprisetrack oracle:instantis_enterprisetrack | 17.1; 17.2; 17.3 | NVD |
oracle mysql_enterprise_monitor oracle:mysql_enterprise_monitor | before 8.0.23 | NVD |
oracle sd-wan_edge oracle:sd-wan_edge | 9.0 | NVD |
oracle workload_manager oracle:workload_manager | 18c; 19c | NVD |
References
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3Ex-refsource-misc
- https://lists.apache.org/thread.html/r8a227ac6a755a6406c1cc47dd48800e973d4cf13fe7fe68ac59c679c%40%3Cdev.tomcat.apache.org%3Emailing-list, x-refsource-mlist
- https://lists.apache.org/thread.html/raa0e9ad388c1e6fd1e301b5e080f9439f64cb4178119a86a4801cc53%40%3Cdev.tomcat.apache.org%3Emailing-list, x-refsource-mlist
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.apache.org%3Emailing-list, x-refsource-mlist
- https://lists.apache.org/thread.html/rd5babd13d7a350b369b2f647b4dd32ce678af42f9aba5389df1ae6ca%40%3Cusers.tomcat.apache.org%3Emailing-list, x-refsource-mlist
- http://www.openwall.com/lists/oss-security/2020/12/03/3mailing-list, x-refsource-mlist
- https://lists.apache.org/thread.html/rabbe6b3ae6a9795641d7a05c00d2378d5bbbe4240b7e20f09b092cce%40%3Cissues.guacamole.apache.org%3Emailing-list, x-refsource-mlist
- https://lists.apache.org/thread.html/ra35c8d617b17d59f400112cebadec43ad379f98198b4a9726190d7ee%40%3Cissues.guacamole.apache.org%3Emailing-list, x-refsource-mlist
- https://lists.apache.org/thread.html/r9fd47f1b03e9b41d16a5cf72659b533887267d3398d963c2fff3abfa%40%3Ccommits.tomee.apache.org%3Emailing-list, x-refsource-mlist
- https://lists.apache.org/thread.html/r26a2a66339087fc37db3caf201e446d3e83b5cce314371e235ff1784%40%3Ccommits.tomee.apache.org%3Emailing-list, x-refsource-mlist
- https://lists.debian.org/debian-lts-announce/2020/12/msg00022.htmlmailing-list, x-refsource-mlist
- https://security.gentoo.org/glsa/202012-23vendor-advisory, x-refsource-gentoo
- https://lists.apache.org/thread.html/rca833c6d42b7b9ce1563488c0929f29fcc95947d86e5e740258c8937%40%3Cdev.tomcat.apache.org%3Emailing-list, x-refsource-mlist
- https://lists.apache.org/thread.html/ra9fcdb904dd2e2256ef90b3e4ced279cd464cb0ab63a6c64df5c010d%40%3Cannounce.apache.org%3Emailing-list, x-refsource-mlist
- https://lists.apache.org/thread.html/r5a285242737ddef4d338236328aaaf3237183e1465a5efafd16b99ed%40%3Cdev.tomcat.apache.org%3Emailing-list, x-refsource-mlist
- https://lists.apache.org/thread.html/ra9fcdb904dd2e2256ef90b3e4ced279cd464cb0ab63a6c64df5c010d%40%3Cannounce.tomcat.apache.org%3Emailing-list, x-refsource-mlist
- https://lists.apache.org/thread.html/rbba08c4dcef3603e36276d49adda8eedbe458c5104314b4038f697e1%40%3Cusers.tomcat.apache.org%3Emailing-list, x-refsource-mlist
- https://www.debian.org/security/2021/dsa-4835vendor-advisory, x-refsource-debian
- https://lists.apache.org/thread.html/r2d6e05c5ff96f8068a59dfdb3800e9ee8d4e36ce1971783c6e5f9b20%40%3Ccommits.tomee.apache.org%3Emailing-list, x-refsource-mlist
- https://www.oracle.com/security-alerts/cpuApr2021.htmlx-refsource-misc
- https://security.netapp.com/advisory/ntap-20201210-0003/x-refsource-confirm
- https://www.oracle.com//security-alerts/cpujul2021.htmlx-refsource-misc
- https://www.oracle.com/security-alerts/cpujan2022.htmlx-refsource-misc
- https://www.oracle.com/security-alerts/cpuapr2022.htmlx-refsource-misc
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.