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Full vulnerability report · 2020
CVE-2020-11080High confidence

Denial of service in nghttp2

nghttp2 · nghttp2

Official source article: GitHub GHSA-Q5WR-XFW9-Q7XR ↗. Check the applicable product and release in the original source.

3.7LowCVSS 3.1
Recommended action
Scheduled

Low technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityLowOperational priority:Low, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 5.32% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs nghttp2 nghttp2 and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: No default targetRemediation target: Normal maintenance

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Distribution package intelligence

Release-specific package status

Alpine, Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

17 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Alpine v3.23v3.23 · communitynodejs-currentVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.14.4.0-r0Alpine Security Database ↗Source updated 11 Sep 2026
Alpine v3.23v3.23 · mainnghttp2Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.1.41.0-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.23v3.23 · mainnodejsVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.12.18.0-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.22v3.22 · communitynodejs-currentVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.14.4.0-r0Alpine Security Database ↗Source updated 11 Sep 2026
Alpine v3.22v3.22 · mainnghttp2Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.1.41.0-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.22v3.22 · mainnodejsVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.12.18.0-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.21v3.21 · communitynodejs-currentVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.14.4.0-r0Alpine Security Database ↗Source updated 19 Aug 2026
Alpine v3.21v3.21 · mainnghttp2Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.1.41.0-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.21v3.21 · mainnodejsVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.12.18.0-r0Alpine Security Database ↗Source updated 3 Oct 2026
Debian trixietrixie · sourcenghttp2Vendor fix publishedDebian records a fixed source-package version for this release.1.41.0-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian trixietrixie · sourcenodejsVendor fix publishedDebian records a fixed source-package version for this release.10.21.0~dfsg-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian bookwormbookworm · sourcenghttp2Vendor fix publishedDebian records a fixed source-package version for this release.1.41.0-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian bookwormbookworm · sourcenodejsVendor fix publishedDebian records a fixed source-package version for this release.10.21.0~dfsg-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian forkyforky · sourcenghttp2Vendor fix publishedDebian records a fixed source-package version for this release.1.41.0-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian forkyforky · sourcenodejsVendor fix publishedDebian records a fixed source-package version for this release.10.21.0~dfsg-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian sidsid · sourcenghttp2Vendor fix publishedDebian records a fixed source-package version for this release.1.41.0-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian sidsid · sourcenodejsVendor fix publishedDebian records a fixed source-package version for this release.10.21.0~dfsg-1Debian Security Tracker ↗Source updated 6 Oct 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2020-11080 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitynghttp2: overly large SETTINGS frames can lead to DoS
510 fixed

The vendor explicitly identifies these products or versions as containing the fix.

  • jbcs-httpd24-curl-0:7.64.1-36.jbcs.el6.i686 as a component of Red Hat JBoss Core Services on RHEL 6 Server
  • jbcs-httpd24-curl-0:7.64.1-36.jbcs.el6.src as a component of Red Hat JBoss Core Services on RHEL 6 Server
  • jbcs-httpd24-curl-0:7.64.1-36.jbcs.el6.x86_64 as a component of Red Hat JBoss Core Services on RHEL 6 Server
  • jbcs-httpd24-curl-debuginfo-0:7.64.1-36.jbcs.el6.i686 as a component of Red Hat JBoss Core Services on RHEL 6 Server
  • jbcs-httpd24-curl-debuginfo-0:7.64.1-36.jbcs.el6.x86_64 as a component of Red Hat JBoss Core Services on RHEL 6 Server
  • jbcs-httpd24-httpd-0:2.4.37-57.jbcs.el6.i686 as a component of Red Hat JBoss Core Services on RHEL 6 Server
  • jbcs-httpd24-httpd-0:2.4.37-57.jbcs.el6.src as a component of Red Hat JBoss Core Services on RHEL 6 Server
  • jbcs-httpd24-httpd-0:2.4.37-57.jbcs.el6.x86_64 as a component of Red Hat JBoss Core Services on RHEL 6 Server
  • jbcs-httpd24-httpd-debuginfo-0:2.4.37-57.jbcs.el6.i686 as a component of Red Hat JBoss Core Services on RHEL 6 Server
  • jbcs-httpd24-httpd-debuginfo-0:2.4.37-57.jbcs.el6.x86_64 as a component of Red Hat JBoss Core Services on RHEL 6 Server
  • jbcs-httpd24-httpd-devel-0:2.4.37-57.jbcs.el6.i686 as a component of Red Hat JBoss Core Services on RHEL 6 Server
  • jbcs-httpd24-httpd-devel-0:2.4.37-57.jbcs.el6.x86_64 as a component of Red Hat JBoss Core Services on RHEL 6 Server
Summary
A resource consumption vulnerability was found in nghttp2. This flaw allows an attacker to repeatedly construct an overly large HTTP/2 SETTINGS frame with a length of 14,400 bytes that causes excessive CPU usage, leading to a denial of service.
Remediation
Before applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2020-3444

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Low technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

In nghttp2 before version 1.41.0, the overly large HTTP/2 SETTINGS frame payload causes denial of service. The proof of concept attack involves a malicious client constructing a SETTINGS frame with a length of 14,400 bytes (2400 individual settings entries) over and over again. The attack causes the CPU to spike at 100%. nghttp2 v1.41.0 fixes this vulnerability. There is a workaround to this vulnerability. Implement nghttp2_on_frame_recv_callback callback, and if received frame is SETTINGS frame and the number of settings entries are large (e.g., > 32), then drop the connection.

What

In nghttp2 before version 1.41.0, the overly large HTTP/2 SETTINGS frame payload causes denial of service. The proof of concept attack involves a malicious client constructing a SETTINGS frame with a length of 14,400 bytes (2400 individual settings entries) over and over again. The attack causes the CPU to spike at 100%. nghttp2 v1.41.0 fixes this vulnerability. There is a workaround to this vulnerability. Implement nghttp2_on_frame_recv_callback callback, and if received frame is SETTINGS frame and the number of settings entries are large (e.g., > 32), then drop the connection.

Why

The product does not ensure or incorrectly ensures that structured messages or data are well-formed and that certain security properties are met before being read from an upstream component or sent to a downstream component.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

What

In nghttp2 before version 1.41.0, the overly large HTTP/2 SETTINGS frame payload causes denial of service. The proof of concept attack involves a malicious client constructing a SETTINGS frame with a length of 14,400 bytes (2400 individual settings entries) over and over again. The attack causes the CPU to spike at 100%. nghttp2 v1.41.0 fixes this vulnerability. There is a workaround to this vulnerability. Implement nghttp2_on_frame_recv_callback callback, and if received frame is SETTINGS frame and the number of settings entries are large (e.g., > 32), then drop the connection.

Why

The product does not ensure or incorrectly ensures that structured messages or data are well-formed and that certain security properties are met before being read from an upstream component or sent to a downstream component.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Neutralization → disrupt the affected service
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-707 ↗

CWE-707: Improper Neutralization. The product does not ensure or incorrectly ensures that structured messages or data are well-formed and that certain security properties are met before being read from an upstream component or sent to a downstream component.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.ALowAvailability impact: A successful attack can cause a limited loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedDenial of serviceCWE-707
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2025-0227IBM QRadar SIEM: Mehrere Schwachstellen

Ein entfernter, authentisierter Angreifer kann mehrere Schwachstellen in IBM QRadar SIEM ausnutzen, um seine Privilegien zu erweitern, Administratorrechte zu erlangen, beliebigen Programmcode auszuführen, Informationen offenzulegen, Dateien zu manipulieren oder Sicherheitsvorkehrungen zu umgehen.

Official advisory ↗
BSI · German · WID-SEC-2026-0205Oracle MySQL: Mehrere Schwachstellen

Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Oracle MySQL ausnutzen, um die Verfügbarkeit, Vertraulichkeit und Integrität zu gefährden.

Official advisory ↗
BSI · German · WID-SEC-2023-1374Node.js: Mehrere Schwachstellen

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Node.js ausnutzen, um beliebigen Programmcode auszuführen, einen Denial of Service Angriff durchzuführen, Sicherheitsmechanismen zu umgehen oder seine Privilegien zu erweitern.

Official advisory ↗
Canadian Centre for Cyber Security · English · AV20-310IBM security advisory

Between 17 and 23 August 2020 IBM released Security Bulletins to address vulnerabilities in multiple products. Included were critical patches for the following: IBM Spectrum Protect Plus

Official advisory ↗
Canadian Centre for Cyber Security · English · AV20-293IBM security advisory

Between 3 and 10 August 2020 IBM released Security Bulletins to address vulnerabilities in multiple products. Included were critical patches for the following: IBM Netcool Operations Insight https://www.ibm.com/blogs/psirt/security-bulletin-version-10-19-0-of-node-js-included-in-ibm-netcool-operations-insight-1-6-0-x-has-several-security-vulnerabilities/

Official advisory ↗
Canadian Centre for Cyber Security · English · AV20-281IBM security advisory

Between 27 July and 3 August 2020 IBM released Security Bulletins to address vulnerabilities in multiple products. Included were critical patches for the following: IBM Security Guardium https://www.ibm.com/blogs/psirt/security-bulletin-ibm-security-guardium-is-affected-by-a-use-of-insufficiently-random-value-vulnerability-2/

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20200610Security Bulletin 10 Jun 2020

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 10 Jun 2020, published on 10 June 2020. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2020-006097nghttp2 におけるメッセージまたはデータ構造の不適切な強制に関する脆弱性

nghttp2 には、メッセージまたはデータ構造の不適切な強制に関する脆弱性が存在します。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
nghttp2: < 1.41.0
Fixed
Action
Before applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 3 Jun 2020 · Last source change 9 Jun 2025, 15:45 UTC · CWE-707 · Improper Neutralization

CVE recordCVE.org · 5.1
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2020-3444
Product sourceCNA
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    < 1.41.0 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    After
    < 1.41.0 · Fixed: Before applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
    Red Hat Product Security ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2020-3444↗Red Hat Product Security security advisory↗Patch or update reference · GitHub GHSA-Q5WR-XFW9-Q7XR↗Patch or update reference↗Patch or update reference↗Patch or update reference↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2020-11080 · cve.blacktree.nl