In Apache Tomcat 9.0.0.M1 to 9.0.30, 8.5.0 to 8.5.50 and 7.0.0 to 7.0.99 the HTTP header parsing code used an approach to end-of-line parsing that allowed some invalid HTTP headers to be parsed as valid. This led to a possibility of HTTP Request Smuggling if Tomcat was located behind a reverse proxy that incorrectly handled the invalid Transfer-Encoding header in a particular manner. Such a reverse proxy is considered unlikely.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://lists.apache.org/thread.html/r127f76181aceffea2bd4711b03c595d0f115f63e020348fe925a916c%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/r127f76181aceffea2bd4711b03c595d0f115f63e020348fe925a916c%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 4.8 · apache, debian, canonicalNVD modified 2026-10-08 21:17
Affected (CPE criteria) 57
cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:-:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone1:*:*:*:*:*:*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:milestone2:*:*:*:*:*:*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:milestone3:*:*:*:*:*:*cpe:2.3:a:apache:tomcat:9.0.0:milestone4:*:*:*:*:*:*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:o:debian:debian_linux:8.0:*:*:*:*:*:*:*cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*cpe:2.3:a:netapp:data_availability_services:-:*:*:*:*:*:*:*cpe:2.3:a:netapp:oncommand_system_manager:*:*:*:*:*:*:*:*cpe:2.3:a:oracle:agile_engineering_data_management:6.2.1.0:*:*:*:*:*:*:*cpe:2.3:a:oracle:agile_product_lifecycle_management:9.3.3:*:*:*:*:*:*:*cpe:2.3:a:oracle:agile_product_lifecycle_management:9.3.5:*:*:*:*:*:*:*cpe:2.3:a:oracle:agile_product_lifecycle_management:9.3.6:*:*:*:*:*:*:*- and 17 more
References 38
- http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00025.html Broken Link, Mailing List, Third Party Advisory
- https://lists.apache.org/thread.html/r127f76181aceffea2bd4711b03c595d0f115f63e020348fe925a916c%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/r441c1f30a252bf14b07396286f6abd8089ce4240e91323211f1a2d75%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r660cd379afe346f10d72c0eaa8459ccc95d83aff181671b7e9076919%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r7bc994c965a34876bd94d5ff15b4e1e30b6220a15eb9b47c81915b78%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/r80e9c8417c77d52c62809168b96912bda70ddf7748f19f8210f745b1%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r9ce7918faf347e7aac32be930bf26c233b0b140fe37af0bb294158b6%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/ra5dee390ad2d60307b8362505c059cd6a726de4d146d63dfce1e05e7%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rc31cbabb46cdc58bbdd8519a8f64b6236b2635a3922bbeba0f0e3743%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/rd547be0c9d821b4b1000a694b8e58ef9f5e2d66db03a31dfe77c4b18%40%3Cusers.tomcat.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2020/03/msg00006.html Mailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2020/05/msg00026.html Mailing List, Third Party Advisory
- https://security.netapp.com/advisory/ntap-20200327-0005/ Third Party Advisory
- https://usn.ubuntu.com/4448-1/ Third Party Advisory
- https://www.debian.org/security/2020/dsa-4673 Third Party Advisory
- https://www.debian.org/security/2020/dsa-4680 Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2021.html Third Party Advisory
- https://www.oracle.com/security-alerts/cpujul2020.html Third Party Advisory
- https://www.oracle.com/security-alerts/cpuoct2020.html Third Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00025.html Broken Link, Mailing List, Third Party Advisory
- https://lists.apache.org/thread.html/r127f76181aceffea2bd4711b03c595d0f115f63e020348fe925a916c%40%3Cannounce.tomcat.apache.org%3E Mailing List, Vendor Advisory
- https://lists.apache.org/thread.html/r441c1f30a252bf14b07396286f6abd8089ce4240e91323211f1a2d75%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r660cd379afe346f10d72c0eaa8459ccc95d83aff181671b7e9076919%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r7bc994c965a34876bd94d5ff15b4e1e30b6220a15eb9b47c81915b78%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/r80e9c8417c77d52c62809168b96912bda70ddf7748f19f8210f745b1%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r9ce7918faf347e7aac32be930bf26c233b0b140fe37af0bb294158b6%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/ra5dee390ad2d60307b8362505c059cd6a726de4d146d63dfce1e05e7%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rc31cbabb46cdc58bbdd8519a8f64b6236b2635a3922bbeba0f0e3743%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/rd547be0c9d821b4b1000a694b8e58ef9f5e2d66db03a31dfe77c4b18%40%3Cusers.tomcat.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2020/03/msg00006.html Mailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2020/05/msg00026.html Mailing List, Third Party Advisory
- https://security.netapp.com/advisory/ntap-20200327-0005/ Third Party Advisory
- https://usn.ubuntu.com/4448-1/ Third Party Advisory
- https://www.debian.org/security/2020/dsa-4673 Third Party Advisory
- https://www.debian.org/security/2020/dsa-4680 Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2021.html Third Party Advisory
- https://www.oracle.com/security-alerts/cpujul2020.html Third Party Advisory
- https://www.oracle.com/security-alerts/cpuoct2020.html Third Party Advisory