No exploitation reportedFix available

CVE-2020-13934

No exploitation reported by the sources we read.

Published2020-07-14
WeaknessCWE-401 · CWE-476

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

An h2c direct connection to Apache Tomcat 10.0.0-M1 to 10.0.0-M6, 9.0.0.M5 to 9.0.36 and 8.5.1 to 8.5.56 did not release the HTTP/1.1 processor after the upgrade to HTTP/2. If a sufficient number of such requests were made, an OutOfMemoryException could occur leading to a denial of service.

Timeline

dates in UTC

2020-07-1415:15CVE publishedNVD
2026-10-2319:23EPSS crossed 10 %FIRST EPSS

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-13934?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-13934?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Apache Tomcat

Branch	Affected	Fixed in	Source
9.0	= 9.0.0	no fix published	NVD
8.5	≥ 8.5.1, ≤ 8.5.56	no fix published	NVD
9.0	≥ 9.0.1, ≤ 9.0.36	no fix published	NVD
10.0	= 10.0.0	no fix published	NVD

Oracle agile product lifecycle management

Branch	Affected	Fixed in	Source
9.3	= 9.3.3	no fix published	NVD
9.3	= 9.3.5	no fix published	NVD
9.3	= 9.3.6	no fix published	NVD

Oracle instantis enterprisetrack

Branch	Affected	Fixed in	Source
17.1	= 17.1	no fix published	NVD
17.2	= 17.2	no fix published	NVD
17.3	= 17.3	no fix published	NVD

11 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

lists.apache.orgRelease Notes · Vendor Advisory
www.oracle.comPatch
www.oracle.comPatch
www.oracle.comPatch
www.oracle.comPatch
www.oracle.comPatch

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CISA-ADPSSVC decisionnone2026-10-08
OpenCVESSVC decisionnone—
NVDCVSS 3.17.5read 2026-10-23
NVDCVSS 2.05read 2026-10-23
NVDweakness (CWE)CWE-401, CWE-476read 2026-10-23
FIRST EPSSEPSS score64.1 %read 2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2020-07-14
Last Modified: 2026-10-08
NVD status: Modified

Frequently asked questions

What is CVE-2020-13934?

Is CVE-2020-13934 actively exploited?

Active exploitation of CVE-2020-13934 has not been confirmed. Its EPSS score was 64.1% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-13934?

CVE-2020-13934 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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