Some HTTP/2 implementations are vulnerable to window size manipulation and stream prioritization manipulation, potentially leading to a denial of service
Noroxi assessment
Priority: Plan (action score 48/100)
- Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
- Probability of exploitation in the next 30 days: 59.5% (FIRST EPSS); higher than 99.1% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: nginx (AlmaLinux:8) 1:1.14.1-9.module_el8.5.0+34+dc1cfba5.alma, 1:1.14.1-9.module_el8.4.0+2221+af250afe.alma, 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma; nginx-all-modules (AlmaLinux:8) 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma; nginx-filesystem (AlmaLinux:8) 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma.
- Mentioned 4 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Add it to your regular patch cycle. Upgrade to nginx (AlmaLinux:8) 1:1.14.1-9.module_el8.5.0+34+dc1cfba5.alma, 1:1.14.1-9.module_el8.4.0+2221+af250afe.alma, 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma; nginx-all-modules (AlmaLinux:8) 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma; nginx-filesystem (AlmaLinux:8) 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
Some HTTP/2 implementations are vulnerable to window size manipulation and stream prioritization manipulation, potentially leading to a denial of service. The attacker requests a large amount of data from a specified resource over multiple streams. They manipulate window size and stream priority to force the server to queue the data in 1-byte chunks. Depending on how efficiently this data is queued, this can consume excess CPU, memory, or both.
- BDU:2019-02994
- BDU:2019-03782
- ALSA-2019:2799
- ALSA-2019:2925
- DSA-4505-1
- DSA-4511-1
- DSA-4669-1
- openSUSE-SU-2019:2114-1
- openSUSE-SU-2019:2115-1
- openSUSE-SU-2019:2120-1
- openSUSE-SU-2019:2232-1
- openSUSE-SU-2019:2234-1
- openSUSE-SU-2019:2264-1
- openSUSE-SU-2024:11091-1
- openSUSE-SU-2024:11092-1
- RHSA-2019:2692
- RHSA-2019:2745
- RHSA-2019:2746
- RHSA-2019:2775
- RHSA-2019:2799
- Published
- Aug 13, 2019
- Updated
- Jun 16, 2026
- EPSS
- 59.5% · 99th percentile
- CWE
- CWE-400
Report tools
Action score
48
Plan
Add it to your regular patch cycle.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 18 / 30 · 59.5%
CNA vs NVD score
- NVD
- 7.5
- CNA · certcc
- 7.5
- agree
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- Proof of concept exists, no weaponized module
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| apple | swiftnio | cpe:2.3:a:apple:swiftnio |
| apple | mac os x | cpe:2.3:o:apple:mac_os_x |
| canonical | ubuntu linux | cpe:2.3:o:canonical:ubuntu_linux |
| apache | traffic server | cpe:2.3:a:apache:traffic_server |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
| synology | skynas | cpe:2.3:a:synology:skynas |
| synology | diskstation manager | cpe:2.3:o:synology:diskstation_manager |
| synology | vs960hd firmware | cpe:2.3:o:synology:vs960hd_firmware |
| synology | vs960hd | cpe:2.3:h:synology:vs960hd |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
| opensuse | leap | cpe:2.3:o:opensuse:leap |
| redhat | jboss core services | cpe:2.3:a:redhat:jboss_core_services |
and 10 more
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- f5 nginx1.9.5 and later · before 1.16.1
- f5 nginx1.17.0 and later · up to 1.17.2 inclusive
- nodejs node.js8.0.0 and later · up to 8.8.1 inclusive
- nodejs node.js8.9.0 and later · before 8.16.1
- nodejs node.js10.0.0 and later · up to 10.12.0 inclusive
- nodejs node.js10.13.0 and later · before 10.16.3
- nodejs node.js12.0.0 and later · before 12.8.1
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | nginx | before 1:1.14.1-9.module_el8.5.0+34+dc1cfba5.alma | 1:1.14.1-9.module_el8.5.0+34+dc1cfba5.alma |
| AlmaLinux:8 | nginx | before 1:1.14.1-9.module_el8.4.0+2221+af250afe.alma | 1:1.14.1-9.module_el8.4.0+2221+af250afe.alma |
| AlmaLinux:8 | nginx | before 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma | 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma |
| AlmaLinux:8 | nginx-all-modules | before 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma | 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma |
| AlmaLinux:8 | nginx-filesystem | before 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma | 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma |
| AlmaLinux:8 | nginx-mod-http-image-filter | before 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma | 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma |
| AlmaLinux:8 | nginx-mod-http-image-filter | before 1:1.14.1-9.module_el8.5.0+34+dc1cfba5.alma | 1:1.14.1-9.module_el8.5.0+34+dc1cfba5.alma |
| AlmaLinux:8 | nginx-mod-http-image-filter | before 1:1.14.1-9.module_el8.4.0+2221+af250afe.alma | 1:1.14.1-9.module_el8.4.0+2221+af250afe.alma |
| AlmaLinux:8 | nginx-mod-http-perl | before 1:1.14.1-9.module_el8.4.0+2221+af250afe.alma | 1:1.14.1-9.module_el8.4.0+2221+af250afe.alma |
| AlmaLinux:8 | nginx-mod-http-perl | before 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma | 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma |
| AlmaLinux:8 | nginx-mod-http-perl | before 1:1.14.1-9.module_el8.5.0+34+dc1cfba5.alma | 1:1.14.1-9.module_el8.5.0+34+dc1cfba5.alma |
| AlmaLinux:8 | nginx-mod-http-xslt-filter | before 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma | 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma |
| AlmaLinux:8 | nginx-mod-http-xslt-filter | before 1:1.14.1-9.module_el8.4.0+2221+af250afe.alma | 1:1.14.1-9.module_el8.4.0+2221+af250afe.alma |
| AlmaLinux:8 | nginx-mod-http-xslt-filter | before 1:1.14.1-9.module_el8.5.0+34+dc1cfba5.alma | 1:1.14.1-9.module_el8.5.0+34+dc1cfba5.alma |
| AlmaLinux:8 | nginx-mod-mail | before 1:1.14.1-9.module_el8.5.0+34+dc1cfba5.alma | 1:1.14.1-9.module_el8.5.0+34+dc1cfba5.alma |
| AlmaLinux:8 | nginx-mod-mail | before 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma | 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma |
| AlmaLinux:8 | nginx-mod-mail | before 1:1.14.1-9.module_el8.4.0+2221+af250afe.alma | 1:1.14.1-9.module_el8.4.0+2221+af250afe.alma |
| AlmaLinux:8 | nginx-mod-stream | before 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma | 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma |
| AlmaLinux:8 | nginx-mod-stream | before 1:1.14.1-9.module_el8.4.0+2221+af250afe.alma | 1:1.14.1-9.module_el8.4.0+2221+af250afe.alma |
| AlmaLinux:8 | nginx-mod-stream | before 1:1.14.1-9.module_el8.5.0+34+dc1cfba5.alma | 1:1.14.1-9.module_el8.5.0+34+dc1cfba5.alma |
| AlmaLinux:8 | nodejs-nodemon | before 1.18.3-1.module_el8.3.0+2023+d2377ea3 | 1.18.3-1.module_el8.3.0+2023+d2377ea3 |
| AlmaLinux:8 | nodejs-nodemon | before 1.18.3-1.module_el8.3.0+2047+b07ac28e | 1.18.3-1.module_el8.3.0+2047+b07ac28e |
| AlmaLinux:8 | nodejs-packaging | before 17-3.module_el8.4.0+2224+b07ac28e | 17-3.module_el8.4.0+2224+b07ac28e |
| AlmaLinux:8 | nodejs-packaging | before 17-3.module_el8.4.0+2521+c668cc9f | 17-3.module_el8.4.0+2521+c668cc9f |
+96
Same product
apple: all recordsOther highest-scoring records for the same primary product.
- CVE-2019-9515Some HTTP/2 implementations are vulnerable to a settings flood, potentially leading to a denial of service56Plan
- CVE-2019-9514Some HTTP/2 implementations are vulnerable to a reset flood, potentially leading to a denial of service55Plan
- CVE-2019-9512Some HTTP/2 implementations are vulnerable to ping floods, potentially leading to a denial of service55Plan
- CVE-2019-9513Some HTTP/2 implementations are vulnerable to resource loops, potentially leading to a denial of service54Plan
- CVE-2019-9516Some HTTP/2 implementations are vulnerable to a header leak, potentially leading to a denial of service43Plan
- CVE-2018-4281In SwiftNIO before 1.8.0, a buffer overflow was addressed with improved size validation.39Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| almalinux:nginx | 1:1.14.1-9.module_el8.5.0+34+dc1cfba5.alma · AlmaLinux:8 | Package registry (OSV) |
| almalinux:nginx-all-modules | 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma · AlmaLinux:8 | Package registry (OSV) |
| almalinux:nginx-filesystem | 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma · AlmaLinux:8 | Package registry (OSV) |
| almalinux:nginx-mod-http-image-filter | 1:1.14.1-9.module_el8.4.0+2221+af250afe.alma · AlmaLinux:8 | Package registry (OSV) |
| almalinux:nginx-mod-http-perl | 1:1.14.1-9.module_el8.4.0+2221+af250afe.alma · AlmaLinux:8 | Package registry (OSV) |
| almalinux:nginx-mod-http-xslt-filter | 1:1.14.1-9.module_el8.4.0+2221+af250afe.alma · AlmaLinux:8 | Package registry (OSV) |
| almalinux:nginx-mod-mail | 1:1.14.1-9.module_el8.4.0+2221+af250afe.alma · AlmaLinux:8 | Package registry (OSV) |
| almalinux:nginx-mod-stream | 1:1.14.1-9.module_el8.3.0+2165+af250afe.alma · AlmaLinux:8 | Package registry (OSV) |
| almalinux:nodejs-nodemon | 1.18.3-1.module_el8.3.0+2023+d2377ea3 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:nodejs-packaging | 17-3.module_el8.4.0+2224+b07ac28e · AlmaLinux:8 | Package registry (OSV) |
| alpine:nghttp2 | 1.39.2-r0 · Alpine:v3.10 | Package registry (OSV) |
| alpine:nginx | 1.16.1-r0 · Alpine:v3.10 | Package registry (OSV) |
| alpine:nodejs | 10.16.3-r0 · Alpine:v3.10 | Package registry (OSV) |
| debian:nghttp2 | 1.39.2-1 · Debian:12 | Package registry (OSV) |
| debian:nginx | 1.14.2-3 · Debian:12 | Package registry (OSV) |
| debian:nodejs | 10.16.3~dfsg-1 · Debian:12 | Package registry (OSV) |
| opensuse:nghttp2 | 1.39.2-lp151.3.3.1 · openSUSE:Leap 15.1 | Package registry (OSV) |
| opensuse:nghttp2-python | 1.39.2-lp151.3.3.1 · openSUSE:Leap 15.1 | Package registry (OSV) |
| opensuse:nginx | 1.14.2-lp151.4.3.1 · openSUSE:Leap 15.1 | Package registry (OSV) |
| opensuse:nodejs10 | 10.16.3-lp151.2.6.1 · openSUSE:Leap 15.0 | Package registry (OSV) |
| opensuse:nodejs8 | 8.16.1-lp151.2.6.1 · openSUSE:Leap 15.0 | Package registry (OSV) |
| red hat:libnghttp2 | 0:1.33.0-1.el8_0.1 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:libnghttp2-debuginfo | 0:1.33.0-1.el8_0.1 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:libnghttp2-devel | 0:1.33.0-1.el8_0.1 · Red Hat:enterprise_linux:8::crb | Package registry (OSV) |
| red hat:nghttp2 | 0:1.33.0-1.el8_0.1 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:nghttp2-debuginfo | 0:1.33.0-1.el8_0.1 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:nghttp2-debugsource | 0:1.33.0-1.el8_0.1 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:rh-nginx110-nginx | 1:1.10.2-9.el6.1 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:rh-nginx110-nginx-debuginfo | 1:1.10.2-9.el6.1 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:rh-nginx110-nginx-mod-http-image-filter | 1:1.10.2-9.el6.1 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
+11
Exploit status
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Proof-of-concept repository on GitHub ×2
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Proof-of-concept repository on GitHub | stars:1 | 2020-12-22 |
| Proof-of-concept repository on GitHub | stars:0 | 2026-04-29 |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Published
- First PoC+496 d
- TodayOct 18, 2026+2623 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Jonathan LooneyNetflix
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-20-792 · Sep 30, 2020(Node JS Güvenlik Güncellemesi)
- TR-19-174 · Sep 30, 2019(Apache httpd 2 Sunucu Güvenlik Güncellemesi)
- TR-19-138 · Sep 10, 2019(NGINX Sunucu Güvenlik Güncellemesi)
- TR-19-115 · Aug 22, 2019(NGINX Sunucu Güvenlik Güncellemesi)
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-400 · Uncontrolled Resource ConsumptionCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Root cause
Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.
The bug in code
The whole CWE-400 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
function expand(node) { return node.children.map(expand);}Fixed
const MAX_DEPTH = 32;function expand(node, depth = 0) { if (depth > MAX_DEPTH) throw new Error("too deep"); return node.children.map((c) => expand(c, depth + 1));}Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (19 more)Show less
- lists.opensuse.org/opensuse-security-announce/2019-09/msg00032.html
- lists.opensuse.org/opensuse-security-announce/2019-09/msg00035.html
- lists.opensuse.org/opensuse-security-announce/2019-10/msg00003.html
- lists.opensuse.org/opensuse-security-announce/2019-10/msg00005.html
- lists.opensuse.org/opensuse-security-announce/2019-10/msg00014.html
- access.redhat.com/errata/RHSA-2019:2692
- access.redhat.com/errata/RHSA-2019:2745
- access.redhat.com/errata/RHSA-2019:2746
- access.redhat.com/errata/RHSA-2019:2775
- access.redhat.com/errata/RHSA-2019:2799
- access.redhat.com/errata/RHSA-2019:2925
- access.redhat.com/errata/RHSA-2019:2939
- access.redhat.com/errata/RHSA-2019:2949
- access.redhat.com/errata/RHSA-2019:2955
- access.redhat.com/errata/RHSA-2019:2966
- access.redhat.com/errata/RHSA-2019:3041
- access.redhat.com/errata/RHSA-2019:3932
- access.redhat.com/errata/RHSA-2019:3933
- access.redhat.com/errata/RHSA-2019:3935
Vendor advisories and official records. Exploit/PoC links are deliberately left out.