CVE•Published 2020-10-12•Modified 2026-10-08•1 article on news•5 live references•NVD data

CVE-2020-13943Apache · Tomcat

Vulnerability data via NVD (ingested)

CVSS v3.1

4.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

EPSS percentile

Exploit Prediction Scoring System · top 1% of all CVEs

Description

If an HTTP/2 client connecting to Apache Tomcat 10.0.0-M1 to 10.0.0-M7, 9.0.0.M1 to 9.0.37 or 8.5.0 to 8.5.57 exceeded the agreed maximum number of concurrent streams for a connection (in violation of the HTTP/2 protocol), it was possible that a subsequent request made on that connection could contain HTTP headers - including HTTP/2 pseudo headers - from a previous request rather than the intended headers. This could lead to users seeing responses for unexpected resources.

Timeline

Published 2020-10-12

Modified 2026-10-08

External references

NVD MITRE Exploit-DB trickest/cve VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2020-13943

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product + version

product:"Apache Tomcat" version:"8.5.0"

Version-pinned fingerprint from NVD's first vulnerable CPE.

Shodan · banner/body mention

http.html:"Tomcat"

HTTP body or banner mentions "Tomcat" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2020-13943