Reference page — cumulative record through Monday, October 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2020-1935

CVE-2020-1935MEDIUM

Apache Apache Tomcat — 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 par…

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   H   N   N  U  L  L  N    4.8   .0939   95.4     —

AFFECTED
  Product        Versions                            Fixed
  Apache Tomcat  Apache Tomcat 9.0.0.M1 to 9.0.30 –  —

TIMELINE
  Dec 2   Reserved by apache
  Feb 24  Published (CNA: apache)
  Oct 8   ENRICHED — CVE-2020-1935 (Apache Tomcat). Received CVSS 4.8 and CPE data from NVD.

CWE-444 · CNA: apache · CVSS v3.1 · 19 references · NVD status: Modified

Description

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
December 2, 2019	Reserved	Reserved by apache
February 24, 2020	Published	Published (CNA: apache)
October 8, 2026	ENRICHED	ENRICHED — CVE-2020-1935 (Apache Tomcat). Received CVSS 4.8 and CPE data from NVD.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
Apache	Apache Tomcat	—	Apache Tomcat 9.0.0.M1 to 9.0.30	—

Weaknesses

CWE-444

References (19)

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]

Authoritative record: CVE-2020-1935 at cve.org

Vendors: apache

Weaknesses: CWE-444

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2020-1935 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Monday, October 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.