CVE-2019-0199

The HTTP/2 implementation in Apache Tomcat 9.0.0.M1 to 9.0.14 and 8.5.0 to 8.5.37 accepted streams with excessive numbers of SETTINGS frames and also permitted clients to keep streams open without reading/writing request/response data. By keeping streams open for requests that utilised the Servlet API's blocking I/O, clients were able to cause server-side threads to block eventually leading to thread exhaustion and a DoS.

Published: 2019-04-10 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2019-0199 is rated Moderate Risk (63.8/100): CVSS High severity, with high exploitation likelihood (EPSS 65.58%, 98th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2019-0199

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-28 66.24% 65.58% -0.66%
2 2026-03-04 38.29% 66.24% +27.95%
3 2026-03-01 38.29%

Full EPSS history (44 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-0199

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
10.0 2.9 [email protected]

Weakness enumeration for CVE-2019-0199

GitHub Security Advisory for CVE-2019-0199

GHSA-qcxh-w3j9-58qr · Severity: high · Ecosystem: maven — Apache Tomcat Denial of Service vulnerability

OS Trackers for CVE-2019-0199

vendor priority summary link
debian not yet assigned CVE-2019-0199 not yet assigned priority: Debian including 1 source packages (tomcat9), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2019-0199
redhat high https://access.redhat.com/security/cve/CVE-2019-0199
suse medium https://www.suse.com/security/cve/CVE-2019-0199/
ubuntu medium CVE-2019-0199 medium priority: Ubuntu including 2 source packages (tomcat8, tomcat9), 10 status rows across 5 suites (bionic, cosmic, trusty, upstream, xenial): released 4, DNE 3, not-affected 3. https://ubuntu.com/security/CVE-2019-0199

Affected software / configurations for CVE-2019-0199

Vendor Product Version Raw CPE
apache tomcat >= 8.5.0, <= 8.5.37 cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*
apache tomcat >= 9.0.1, <= 9.0.14 cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone1:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone10:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone11:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone12:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone13:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone14:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone15:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone16:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone17:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone18:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone19:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone2:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone20:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone21:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone3:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone4:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone5:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone6:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone7:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone8:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone9:*:*:*:*:*:*

References for CVE-2019-0199

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2019-06/msg00090.html
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00013.html
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00054.html
http://www.securityfocus.com/bid/107674
https://access.redhat.com/errata/RHSA-2019:3929
https://access.redhat.com/errata/RHSA-2019:3931
https://lists.apache.org/thread.html/158ab719cf60448ddbb074798f09152fdb572fc8f781e70a56118d1a%40%3Cdev.tomcat.apache.org%3E
https://lists.apache.org/thread.html/1dd0a59c1295cc08ce4c9e7edae5ad2268acc9ba55adcefa0532e5ba%40%3Cdev.tomcat.apache.org%3E
https://lists.apache.org/thread.html/4c438fa4c78cb1ce8979077f668ab7145baf83e7c59f2faf7eccf094%40%3Cdev.tomcat.apache.org%3E
https://lists.apache.org/thread.html/6af47120905aa7d8fe12f42e8ff2284fb338ba141d3b77b8c7cb61b3%40%3Cdev.tomcat.apache.org%3E
https://lists.apache.org/thread.html/7bb193bc68b28d21ff1c726fd38bea164deb6333b59eec2eb3661da6%40%3Cusers.tomcat.apache.org%3E
https://lists.apache.org/thread.html/88855876c33f2f9c532ffb75bfee570ccf0b17ffa77493745af9a17a%40%3Cdev.tomcat.apache.org%3E
https://lists.apache.org/thread.html/9fe25f98bac6d66f8a663a15c37a98bc2d8f8bbed1d408791a3e4067%40%3Cusers.tomcat.apache.org%3E
https://lists.apache.org/thread.html/a7a201bd23e67fd3326c9b22b814dd0537d3270b3b54a768e2e7ef50%40%3Cdev.tomcat.apache.org%3E
https://lists.apache.org/thread.html/ac0185ce240a711b542a55bccf9349ab0c2f343d70cf7835e08fabc9%40%3Cannounce.apache.org%3E
https://lists.apache.org/thread.html/cf4eb2bd2083cebb3602a293c653f9a7faa96c86f672c876f25b37ef%40%3Cannounce.apache.org%3E
https://lists.apache.org/thread.html/dddb3590bac28fbe89f69f5ccbe26283d014ddc691abdd042de14600%40%3Cannounce.tomcat.apache.org%3E
https://lists.apache.org/thread.html/df1a2c1b87c8a6c500ecdbbaf134c7f1491c8d79d98b48c6b9f0fa6a%40%3Cannounce.tomcat.apache.org%3E
https://lists.apache.org/thread.html/e1b0b273b6e8ddcc72c9023bc2394b1276fc72664144bf21d0a87995%40%3Cannounce.tomcat.apache.org%3E
https://lists.apache.org/thread.html/e56886e1bac9319ecce81b3612dd7a1a43174a3a741a1c805e16880e%40%3Ccommits.tomee.apache.org%3E
https://lists.apache.org/thread.html/e85e83e9954f169bbb77b44baae5a33d8de878df557bb32b7f793661%40%3Cdev.tomcat.apache.org%3E
https://lists.apache.org/thread.html/e87733036e8c84ea648cdcdca3098f3c8a897e2652c33062b2b1535c%40%3Cusers.tomcat.apache.org%3E
https://lists.apache.org/thread.html/r3bbb800a816d0a51eccc5a228c58736960a9fffafa581a225834d97d%40%3Cdev.tomcat.apache.org%3E
https://lists.apache.org/thread.html/r48c1444845fe15a823e1374674bfc297d5008a5453788099ea14caf0%40%3Cdev.tomcat.apache.org%3E
https://lists.apache.org/thread.html/r6ccee4e849bc77df0840c7f853f6bd09d426f6741247da2b7429d5d9%40%3Cdev.tomcat.apache.org%3E
https://lists.apache.org/thread.html/raba0fabaf4d56d4325ab2aca8814f0b30a237ab83d8106b115ee279a%40%3Cdev.tomcat.apache.org%3E
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NPHQEL5AQ6LZSZD2Y6TYZ4RC3WI7NXJ3/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZQTZ5BJ5F4KV6N53SGNKSW3UY5DBIQ46/
https://seclists.org/bugtraq/2019/Dec/43
https://security.netapp.com/advisory/ntap-20190419-0001/ Third Party Advisory
https://support.f5.com/csp/article/K17321505
https://www.debian.org/security/2019/dsa-4596
https://www.oracle.com/security-alerts/cpuapr2020.html
https://www.oracle.com/security-alerts/cpujan2020.html
https://www.oracle.com/technetwork/security-advisory/cpujul2019-5072835.html
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