ZDF
Sign inSign up

Vulnerabilities

Threat intelligence · CVE-2020-13943

CVE-2020-13943 Apache Tomcat HTTP/2 Request mix-up Apache Tomcat could allow a remote attacker to obtain sensitive information, caused by a flaw when HTTP/2 client exc…

Published Oct 19, 2020 · the affected product

Last checked Nov 1, 2026. A connected source was read within the last 7 days.

Check this week

CVE-2020-13943 is not in CISA KEV. FIRST estimates a 52.64% chance of exploitation in the next 30 days. Check whether you run the affected product.

Gaps on this record

  • No plain product name is stored. The page cannot tell you which product to check.
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Unknown—
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
52.64%
Remediation
Not established
Affected products
See sources for product scope

CVE-2020-13943 Apache Tomcat HTTP/2 Request mix-up Apache Tomcat could allow a remote attacker to obtain sensitive information, caused by a flaw when HTTP/2 client exceeded the agreed maximum number of concurrent streams for a connection. By sending a specially-crafted HTTP request, an attacker could exploit this vulnerability to see the responses for unexpected resources, and use this information to launch further a

No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.

How to fix CVE-2020-13943

  • No stored fix

    No vendor fix text is stored. Use the linked advisory before you change production.

  • Version check

    No version range is stored, so an installed version cannot be checked on this page.

  • Official advisories

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2020-13943 is not in CISA KEV. FIRST estimates a 52.64% chance of exploitation in the next 30 days. Check whether you run the affected product.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 52.64%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Apache Tomcat security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 19, 2020 · AlienVault OTX

    Detected

    CVE-2020-13943 Apache Tomcat HTTP/2 Request mix-up Apache Tomcat could allow a remote attacker to obtain sensitive information, caused by a flaw when HTTP/2 client exceeded the agreed maximum number of concurrent streams for a connection. By sending a specially-crafted HTTP request, an attacker could exploit this vulnerability to see the responses for unexpected resources, and use this information

Sources

References

Freshness

Last verified in this catalog Nov 1, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • AlienVault OTXNov 1, 2026