nginx: Excessive CPU usage via flaw in HTTP/2 implementation
Published Nov 7, 2018
7.5
HIGHCVSS 3.1
EPSS 12.40%
Description
nginx before versions 1.15.6 and 1.14.1 has a vulnerability in the implementation of HTTP/2 that can allow for excessive CPU usage. This issue affects nginx compiled with the ngx_http_v2_module (not compiled by default) if the 'http2' option of the 'listen' directive is used in a configuration file.
Affected products
- Vendor n/a Product Nginx Defaultn/a
- Version 1.14.1StatusaffectedConstraints-
- Version 1.15.6StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| n/a | Nginx | n/a |
|
Configuration 1
Configuration 2
- 9.0
Configuration 3
- 14.04
- 16.04
- 18.04
- 18.10
No data.
Red Hat Software Collections for Red Hat Enterprise Linux 7
rh-nginx112-nginx-1:1.12.1-2.el7.1
Fixed · RHSA-2018:3680
Red Hat Software Collections for Red Hat Enterprise Linux 7
rh-nginx114-nginx-1:1.14.1-1.el7
Fixed · RHSA-2018:3681
Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS
rh-nginx112-nginx-1:1.12.1-2.el7.1
Fixed · RHSA-2018:3680
Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS
rh-nginx114-nginx-1:1.14.1-1.el7
Fixed · RHSA-2018:3681
Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS
rh-nginx112-nginx-1:1.12.1-2.el7.1
Fixed · RHSA-2018:3680
Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS
rh-nginx114-nginx-1:1.14.1-1.el7
Fixed · RHSA-2018:3681
Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS
rh-nginx112-nginx-1:1.12.1-2.el7.1
Fixed · RHSA-2018:3680
Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS
rh-nginx114-nginx-1:1.14.1-1.el7
Fixed · RHSA-2018:3681
CloudForms Management Engine 5
nginx
Not affected
Red Hat Ansible Tower 3
nginx
Not affected
Red Hat Enterprise Linux 8
nginx
Not affected
Red Hat Software Collections
rh-nginx110-nginx
Will not fix
Red Hat Software Collections
rh-nginx18-nginx
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Software Collections for Red Hat Enterprise Linux 7 | rh-nginx112-nginx-1:1.12.1-2.el7.1 | Fixed | RHSA-2018:3680 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7 | rh-nginx114-nginx-1:1.14.1-1.el7 | Fixed | RHSA-2018:3681 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS | rh-nginx112-nginx-1:1.12.1-2.el7.1 | Fixed | RHSA-2018:3680 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS | rh-nginx114-nginx-1:1.14.1-1.el7 | Fixed | RHSA-2018:3681 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS | rh-nginx112-nginx-1:1.12.1-2.el7.1 | Fixed | RHSA-2018:3680 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS | rh-nginx114-nginx-1:1.14.1-1.el7 | Fixed | RHSA-2018:3681 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS | rh-nginx112-nginx-1:1.12.1-2.el7.1 | Fixed | RHSA-2018:3680 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS | rh-nginx114-nginx-1:1.14.1-1.el7 | Fixed | RHSA-2018:3681 |
| CloudForms Management Engine 5 | nginx | Not affected | n/a |
| Red Hat Ansible Tower 3 | nginx | Not affected | n/a |
| Red Hat Enterprise Linux 8 | nginx | Not affected | n/a |
| Red Hat Software Collections | rh-nginx110-nginx | Will not fix | n/a |
| Red Hat Software Collections | rh-nginx18-nginx | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
This issue did not affect the versions of rh-nginx18-nginx as shipped with Red Hat Software Collections as they did not include the vulnerable module ngx_http_v2_module.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
AV:N/AC:L/Au:N/C:N/I:N/A:C
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (53 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 12.40% (0.12400) | 96.09th | v5 (v2026.06.15) |
| Jun 15, 2026 | 12.40% (0.12400) | 95.68th | v5 (v2026.06.15) |
| Mar 4, 2026 | 10.88% (0.10883) | 93.25th | v4 (v2025.03.14) |
| Mar 1, 2026 | 3.51% (0.03506) | 87.44th | v4 (v2025.03.14) |
| Feb 4, 2026 | 10.88% (0.10883) | 93.20th | v4 (v2025.03.14) |
| Feb 1, 2026 | 3.51% (0.03506) | 87.36th | v4 (v2025.03.14) |
| Jan 4, 2026 | 10.88% (0.10883) | 93.14th | v4 (v2025.03.14) |
| Jan 1, 2026 | 3.51% (0.03506) | 87.32th | v4 (v2025.03.14) |
| Dec 28, 2025 | 10.88% (0.10883) | 93.15th | v4 (v2025.03.14) |
| Dec 27, 2025 | 9.26% (0.09263) | 92.49th | v4 (v2025.03.14) |
| Dec 4, 2025 | 10.88% (0.10883) | 93.10th | v4 (v2025.03.14) |
| Dec 1, 2025 | 3.51% (0.03506) | 87.25th | v4 (v2025.03.14) |
| Nov 21, 2025 | 10.88% (0.10883) | 93.09th | v4 (v2025.03.14) |
| Nov 18, 2025 | 21.61% (0.21607) | 95.34th | v4 (v2025.03.14) |
| Nov 4, 2025 | 10.88% (0.10883) | 93.05th | v4 (v2025.03.14) |
| Nov 1, 2025 | 3.51% (0.03506) | 87.16th | v4 (v2025.03.14) |
| Oct 28, 2025 | 10.88% (0.10883) | 93.04th | v4 (v2025.03.14) |
| Oct 27, 2025 | 9.26% (0.09263) | 92.39th | v4 (v2025.03.14) |
| Oct 4, 2025 | 10.88% (0.10883) | 93.10th | v4 (v2025.03.14) |
| Oct 1, 2025 | 3.51% (0.03506) | 87.18th | v4 (v2025.03.14) |
| Sep 4, 2025 | 9.26% (0.09263) | 92.44th | v4 (v2025.03.14) |
| Sep 1, 2025 | 2.44% (0.02439) | 84.67th | v4 (v2025.03.14) |
| Aug 4, 2025 | 9.42% (0.09423) | 92.46th | v4 (v2025.03.14) |
| Aug 1, 2025 | 2.49% (0.02486) | 84.78th | v4 (v2025.03.14) |
| Jul 30, 2025 | 9.42% (0.09423) | 92.46th | v4 (v2025.03.14) |
| Jul 4, 2025 | 11.07% (0.11067) | 93.13th | v4 (v2025.03.14) |
| Jul 1, 2025 | 3.57% (0.03572) | 87.30th | v4 (v2025.03.14) |
| Jun 6, 2025 | 11.07% (0.11067) | 93.07th | v4 (v2025.03.14) |
| Jun 4, 2025 | 6.33% (0.06331) | 90.47th | v4 (v2025.03.14) |
| Jun 1, 2025 | 2.11% (0.02111) | 83.30th | v4 (v2025.03.14) |
| May 4, 2025 | 6.08% (0.06076) | 90.22th | v4 (v2025.03.14) |
| May 1, 2025 | 1.94% (0.01940) | 82.46th | v4 (v2025.03.14) |
| Mar 30, 2025 | 6.08% (0.06076) | 89.81th | v4 (v2025.03.14) |
| Mar 29, 2025 | 14.42% (0.14421) | 90.73th | v4 (v2025.03.14) |
| Mar 17, 2025 | 6.08% (0.06076) | 90.06th | v4 (v2025.03.14) |
| Nov 22, 2024 | 2.54% (0.02542) | 90.54th | v3 (v2023.03.01) |
| Aug 22, 2024 | 3.56% (0.03558) | 91.77th | v3 (v2023.03.01) |
| May 9, 2024 | 2.54% (0.02542) | 90.13th | v3 (v2023.03.01) |
| Mar 30, 2024 | 2.97% (0.02974) | 90.67th | v3 (v2023.03.01) |
| Nov 1, 2023 | 3.57% (0.03572) | 90.56th | v3 (v2023.03.01) |
| Jul 8, 2023 | 4.24% (0.04241) | 91.05th | v3 (v2023.03.01) |
| Mar 7, 2023 | 3.08% (0.03077) | 89.48th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.54% (0.01537) | 74.52th | v2 (v2022.01.01) |
| Feb 23, 2023 | 1.54% (0.01537) | 74.48th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.54% (0.01537) | 72.41th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.54% (0.01537) | 51.33th | v2 (v2022.01.01) |
| Feb 3, 2022 | 0.37% (0.00370) | 3.27th | v1 |
| Jan 6, 2022 | 0.37% (0.00370) | 3.29th | v1 |
| Dec 17, 2021 | 0.37% (0.00370) | 7.26th | v1 |
| Sep 22, 2021 | 2.48% (0.02476) | 78.83th | v1 |
| Sep 21, 2021 | 2.27% (0.02273) | 77.99th | v1 |
| Sep 1, 2021 | 2.07% (0.02069) | 77.27th | v1 |
| Apr 14, 2021 | 2.07% (0.02069) | 0.00th | v1 |
References (15)
- http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00035.html vendor-advisoryx_refsource_SUSEThird Party Advisory
- http://mailman.nginx.org/pipermail/nginx-announce/2018/000220.html x_refsource_MISCMailing ListVendor Advisory
- http://seclists.org/fulldisclosure/2021/Sep/36 mailing-listx_refsource_FULLDISCMailing ListThird Party Advisory
- http://www.securityfocus.com/bid/105868 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1042038 vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
- https://access.redhat.com/errata/RHSA-2018:3680 vendor-advisoryx_refsource_REDHATThird Party Advisory
- https://access.redhat.com/errata/RHSA-2018:3681 vendor-advisoryx_refsource_REDHATThird Party Advisory
- https://access.redhat.com/security/cve/CVE-2018-16844 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1644510 Issue Tracking
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16844 x_refsource_CONFIRMIssue Tracking
- https://nvd.nist.gov/vuln/detail/CVE-2018-16844
- https://support.apple.com/kb/HT212818 x_refsource_CONFIRMThird Party Advisory
- https://usn.ubuntu.com/3812-1/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2018-16844
- https://www.debian.org/security/2018/dsa-4335 vendor-advisoryx_refsource_DEBIANThird Party Advisory
Change history (0)
No recorded changes yet.