01 Record
CVE-2020-17527
Apache Tomcat: Request header mix-up between HTTP/2 streams
UnratedPUBLISHEDCNA: apache
CNA base scoreUnratedNo CNA CVSS vector
02 Description
Apache Tomcat: Request header mix-up between HTTP/2 streams
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 24.62% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 97.6% of scored records. A rank, not a probability.
- NVD base score
- 7.5 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- NVD analysis status
- Modified. NVD last modified this record on 2026-10-08.
- Red Hat severity
- Moderate. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2020-12-03 18:30Z5 YR AGO
- Last updated
- 2026-10-08 21:13Z20 DAYS AGO
- Reserved
- 2020-08-12
- Assigning CNA
- apache
- Record state
- PUBLISHED
- Severity
- Not rated by the issuing CNA
- CNA CVSS vector
- Not published by the issuing CNA
- Weaknesses
- CWE-200Exposure of Sensitive Information to an Unauthorized ActorClass
- Data version
- 5.2
- Document digest
- 03aa4f955d5ab11efc6eec1860930cf446ac8b2bfc4f897f4bddfb568d0ca558
05 Affected products
VendorProductVersionsPlatforms
Apache Software FoundationApache TomcatApache 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—
06 References
- lists.apache.orghttps://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.tomcat.apache.org%3E
- lists.apache.org[tomcat-dev] 20201203 [SECURITY] CVE-2020-17527 Apache Tomcat HTTP/2 Request header mix-uphttps://lists.apache.org/thread.html/r8a227ac6a755a6406c1cc47dd48800e973d4cf13fe7fe68ac59c679c%40%3Cdev.tomcat.apache.org%3E
- lists.apache.org[tomcat-dev] 20201203 svn commit: r1884073 - in /tomcat/site/trunk: docs/security-10.html docs/security-8.html docs/security-9.html xdocs/security-10.xml xdocs/security-8.xml xdocs/security-9.xmlhttps://lists.apache.org/thread.html/raa0e9ad388c1e6fd1e301b5e080f9439f64cb4178119a86a4801cc53%40%3Cdev.tomcat.apache.org%3E
- lists.apache.org[announce] 20201203 [SECURITY] CVE-2020-17527 Apache Tomcat HTTP/2 Request header mix-uphttps://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5%40%3Cannounce.apache.org%3E
- lists.apache.org[tomcat-users] 20201203 [SECURITY] CVE-2020-17527 Apache Tomcat HTTP/2 Request header mix-uphttps://lists.apache.org/thread.html/rd5babd13d7a350b369b2f647b4dd32ce678af42f9aba5389df1ae6ca%40%3Cusers.tomcat.apache.org%3E
- www.openwall.com[oss-security] 20201203 [SECURITY] CVE-2020-17527 Apache Tomcat HTTP/2 Request header mix-uphttp://www.openwall.com/lists/oss-security/2020/12/03/3
- lists.apache.org[guacamole-issues] 20201206 [jira] [Created] (GUACAMOLE-1229) Fix in Dockerhub for latest CVE-2020-17527https://lists.apache.org/thread.html/rabbe6b3ae6a9795641d7a05c00d2378d5bbbe4240b7e20f09b092cce%40%3Cissues.guacamole.apache.org%3E
- lists.apache.org[guacamole-issues] 20201206 [jira] [Commented] (GUACAMOLE-1229) Fix in Dockerhub for latest CVE-2020-17527https://lists.apache.org/thread.html/ra35c8d617b17d59f400112cebadec43ad379f98198b4a9726190d7ee%40%3Cissues.guacamole.apache.org%3E
- lists.apache.org[tomee-commits] 20201207 [jira] [Created] (TOMEE-2936) TomEE plus(7.0.9) is affected by CVE-2020-17527(BDSA-2020-3628) vulnerability.https://lists.apache.org/thread.html/r9fd47f1b03e9b41d16a5cf72659b533887267d3398d963c2fff3abfa%40%3Ccommits.tomee.apache.org%3E
- lists.apache.org[tomee-commits] 20201207 [jira] [Assigned] (TOMEE-2936) TomEE plus(7.0.9) is affected by CVE-2020-17527(BDSA-2020-3628) vulnerability.https://lists.apache.org/thread.html/r26a2a66339087fc37db3caf201e446d3e83b5cce314371e235ff1784%40%3Ccommits.tomee.apache.org%3E
- lists.debian.org[debian-lts-announce] 20201216 [SECURITY] [DLA 2495-1] tomcat8 security updatehttps://lists.debian.org/debian-lts-announce/2020/12/msg00022.html
- security.gentoo.orgGLSA-202012-23https://security.gentoo.org/glsa/202012-23
- lists.apache.org[tomcat-dev] 20210114 svn commit: r1885488 - 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.xmlhttps://lists.apache.org/thread.html/rca833c6d42b7b9ce1563488c0929f29fcc95947d86e5e740258c8937%40%3Cdev.tomcat.apache.org%3E
- lists.apache.org[announce] 20210119 Re: [SECURITY][CORRECTION] CVE-2020-17527 Apache Tomcat HTTP/2 Request header mix-uphttps://lists.apache.org/thread.html/ra9fcdb904dd2e2256ef90b3e4ced279cd464cb0ab63a6c64df5c010d%40%3Cannounce.apache.org%3E
- lists.apache.org[tomcat-dev] 20210119 Re: [SECURITY][CORRECTION] CVE-2020-17527 Apache Tomcat HTTP/2 Request header mix-uphttps://lists.apache.org/thread.html/r5a285242737ddef4d338236328aaaf3237183e1465a5efafd16b99ed%40%3Cdev.tomcat.apache.org%3E
- lists.apache.org[tomcat-announce] 20210119 Re: [SECURITY][CORRECTION] CVE-2020-17527 Apache Tomcat HTTP/2 Request header mix-uphttps://lists.apache.org/thread.html/ra9fcdb904dd2e2256ef90b3e4ced279cd464cb0ab63a6c64df5c010d%40%3Cannounce.tomcat.apache.org%3E
- lists.apache.org[tomcat-users] 20210119 Re: [SECURITY][CORRECTION] CVE-2020-17527 Apache Tomcat HTTP/2 Request header mix-uphttps://lists.apache.org/thread.html/rbba08c4dcef3603e36276d49adda8eedbe458c5104314b4038f697e1%40%3Cusers.tomcat.apache.org%3E
- www.debian.orgDSA-4835https://www.debian.org/security/2021/dsa-4835
- lists.apache.org[tomee-commits] 20210319 [jira] [Updated] (TOMEE-2936) TomEE plus(7.0.9) is affected by CVE-2020-17527(BDSA-2020-3628) vulnerability.https://lists.apache.org/thread.html/r2d6e05c5ff96f8068a59dfdb3800e9ee8d4e36ce1971783c6e5f9b20%40%3Ccommits.tomee.apache.org%3E
- www.oracle.comhttps://www.oracle.com/security-alerts/cpuApr2021.html
- security.netapp.comhttps://security.netapp.com/advisory/ntap-20201210-0003/
- www.oracle.comhttps://www.oracle.com//security-alerts/cpujul2021.html
- www.oracle.comhttps://www.oracle.com/security-alerts/cpujan2022.html
- www.oracle.comhttps://www.oracle.com/security-alerts/cpuapr2022.html
07 Fixed in
Arch Linux
- tomcat9 Fixed in 9.0.40-1
Source: Arch Linux Security Tracker, the Arch Linux security team. Reformatted by exploit.cc.
Debian 12
- tomcat9 Fixed in 9.0.40-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- tomcat9 Fixed in 9.0.40-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- tomcat9 Fixed in 9.0.40-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 18.04 LTS
- tomcat9 Fixed in 9.0.16-3ubuntu0.18.04.2
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 20.04 LTS
- tomcat9 Fixed in 9.0.31-1ubuntu0.2
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 18.04 LTS
- tomcat8 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.