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.
Fix
Public exploits 1
- forse01/CVE-2020-17527-Tomcat PoC on GitHub
Each line links to the index that lists it, never to exploit code. Exploit-DB's "verified" and a Metasploit rank of good or better count as verified; a PoC-in-GitHub entry is a repository's claim.
Patch, vendor advisory and mitigation references on NVD 24
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://www.oracle.com//security-alerts/cpujul2021.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuApr2021.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2022.html Patch, Third Party Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 7.5 · apache, netapp, debianNVD modified 2026-10-08 22:16
Affected (CPE criteria) 54
cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone10:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone11:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone12:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone13:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone14:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone15:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone16:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone17:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone18:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone19:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone20:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone21:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone22:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone23:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone24:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone25:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone26:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone27:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone5:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone6:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone7:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone8:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone9:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.35-3.39.1:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.35-3.57.3:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.36:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.37:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.38:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.39:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:10.0.0:milestone1:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:10.0.0:milestone2:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:10.0.0:milestone3:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:10.0.0:milestone4:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:10.0.0:milestone5:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:10.0.0:milestone6:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:10.0.0:milestone7:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:10.0.0:milestone8:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:10.0.0:milestone9:*:*:*:*:*:*cpe:2.3:a:netapp:element_plug-in:-:*:*:*:*:vcenter_server:*:*- and 14 more
References 62
- http://www.openwall.com/lists/oss-security/2020/12/03/3 Mailing List, Third Party Advisory
- https://lists.apache.org/thread.html/r26a2a66339087fc37db3caf201e446d3e83b5cce314371e235ff1784%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/r2d6e05c5ff96f8068a59dfdb3800e9ee8d4e36ce1971783c6e5f9b20%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/r5a285242737ddef4d338236328aaaf3237183e1465a5efafd16b99ed%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r8a227ac6a755a6406c1cc47dd48800e973d4cf13fe7fe68ac59c679c%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r9fd47f1b03e9b41d16a5cf72659b533887267d3398d963c2fff3abfa%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/ra35c8d617b17d59f400112cebadec43ad379f98198b4a9726190d7ee%40%3Cissues.guacamole.apache.org%3E
- https://lists.apache.org/thread.html/ra9fcdb904dd2e2256ef90b3e4ced279cd464cb0ab63a6c64df5c010d%40%3Cannounce.apache.org%3E
- https://lists.apache.org/thread.html/ra9fcdb904dd2e2256ef90b3e4ced279cd464cb0ab63a6c64df5c010d%40%3Cannounce.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/raa0e9ad388c1e6fd1e301b5e080f9439f64cb4178119a86a4801cc53%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rabbe6b3ae6a9795641d7a05c00d2378d5bbbe4240b7e20f09b092cce%40%3Cissues.guacamole.apache.org%3E
- https://lists.apache.org/thread.html/rbba08c4dcef3603e36276d49adda8eedbe458c5104314b4038f697e1%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rca833c6d42b7b9ce1563488c0929f29fcc95947d86e5e740258c8937%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.apache.org%3E
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rd5babd13d7a350b369b2f647b4dd32ce678af42f9aba5389df1ae6ca%40%3Cusers.tomcat.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2020/12/msg00022.html Mailing List, Third Party Advisory
- https://security.gentoo.org/glsa/202012-23 Third Party Advisory
- https://security.netapp.com/advisory/ntap-20201210-0003/ Third Party Advisory
- https://www.debian.org/security/2021/dsa-4835 Third Party Advisory
- https://www.oracle.com//security-alerts/cpujul2021.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuApr2021.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2022.html Patch, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2020/12/03/3 Mailing List, Third Party Advisory
- https://lists.apache.org/thread.html/r26a2a66339087fc37db3caf201e446d3e83b5cce314371e235ff1784%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/r2d6e05c5ff96f8068a59dfdb3800e9ee8d4e36ce1971783c6e5f9b20%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/r5a285242737ddef4d338236328aaaf3237183e1465a5efafd16b99ed%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r8a227ac6a755a6406c1cc47dd48800e973d4cf13fe7fe68ac59c679c%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r9fd47f1b03e9b41d16a5cf72659b533887267d3398d963c2fff3abfa%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/ra35c8d617b17d59f400112cebadec43ad379f98198b4a9726190d7ee%40%3Cissues.guacamole.apache.org%3E
- https://lists.apache.org/thread.html/ra9fcdb904dd2e2256ef90b3e4ced279cd464cb0ab63a6c64df5c010d%40%3Cannounce.apache.org%3E
- https://lists.apache.org/thread.html/ra9fcdb904dd2e2256ef90b3e4ced279cd464cb0ab63a6c64df5c010d%40%3Cannounce.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/raa0e9ad388c1e6fd1e301b5e080f9439f64cb4178119a86a4801cc53%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rabbe6b3ae6a9795641d7a05c00d2378d5bbbe4240b7e20f09b092cce%40%3Cissues.guacamole.apache.org%3E
- https://lists.apache.org/thread.html/rbba08c4dcef3603e36276d49adda8eedbe458c5104314b4038f697e1%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rca833c6d42b7b9ce1563488c0929f29fcc95947d86e5e740258c8937%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.apache.org%3E
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/rd5babd13d7a350b369b2f647b4dd32ce678af42f9aba5389df1ae6ca%40%3Cusers.tomcat.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2020/12/msg00022.html Mailing List, Third Party Advisory
- https://security.gentoo.org/glsa/202012-23 Third Party Advisory
- https://security.netapp.com/advisory/ntap-20201210-0003/ Third Party Advisory
- https://www.debian.org/security/2021/dsa-4835 Third Party Advisory
- https://www.oracle.com//security-alerts/cpujul2021.html Patch, Third Party Advisory
- https://www.oracle.com/security-alerts/cpuApr2021.html Patch, Third Party Advisory