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Fencer Vulns
high 8.1

CVE-2026-42055 json

NGINX ngx_http_proxy_v2_module and ngx_http_grpc_module vulnerability

published 2026-06-17 4 mo ago modified 2026-09-14 55 d ago also BIT-nginx-2026-42055 , BIT-nginx-gateway-2026-42055 , BIT-nginx-gateway-fabric-2026-42055 , EUVD-2026-37718

cvss
8.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
6.5%
EPSS 6.5% chance of exploitation in 30 days, percentile 93%
public exploits
0
none known

Summary

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules. This vulnerability exists when the proxy_http_version to 2 or grpc_pass directives are used to proxy HTTP/2 traffic, the ignore_invalid_headers directive is set to off, and the large_client_header_buffers directive size is larger than 2 megabytes. A remote, unauthenticated attacker, along with conditions beyond their control, could send large headers while creating an upstream request. This may cause a heap-based buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Patch / fix

  • bitnami nginx 1.30.3, 1.31.2
  • bitnami nginx-gateway 1.30.3, 1.31.2
  • bitnami nginx-gateway-fabric 2.6.4
  • F5 NGINX Open Source 1.30.3, 1.31.2
  • F5 NGINX Plus 37.0.2.1, R36 P6
  • Red Hat Red Hat Enterprise Linux 10 2:1.26.3-6.el10_2.5
  • Red Hat Red Hat Enterprise Linux 8 8100020260707171317.489197e6
  • Red Hat Red Hat Enterprise Linux 9 2:1.20.1-28.el9_8.4, 9080020260707110000.9, 9080020260707164406.9
  • Red Hat Red Hat Discovery 2 1784821750
  • Red Hat Red Hat Hardened Images 1.30.3-2.hum1
  • Red Hat Red Hat Update Infrastructure 5 1784794778, 1784794818, 1784795076, 1787241211, 1787241260
  • nginx Debian 12 1.22.1-9+deb12u9
  • nginx Debian 13 1.26.3-3+deb13u7
  • nginx Debian 14 1.30.1-5

debian advisories DEBIAN-CVE-2026-42055

  • nginx Ubuntu 22.04 LTS 1.18.0-6ubuntu14.16
  • nginx Ubuntu 24.04 LTS 1.24.0-2ubuntu7.13
  • nginx Ubuntu 25.10 1.28.0-6ubuntu1.8
  • nginx Ubuntu 26.04 LTS 1.28.3-2ubuntu1.6

ubuntu advisories UBUNTU-CVE-2026-42055

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • nginx RHEL 8 1:1.24.0-3.module+el8.10.0+24503+61c7c092.3
  • nginx-mod-mail RHEL 8 1:1.24.0-3.module+el8.10.0+24503+61c7c092.3
  • nginx-filesystem RHEL 8 1:1.24.0-3.module+el8.10.0+24503+61c7c092.3
  • nginx-mod-stream RHEL 8 1:1.24.0-3.module+el8.10.0+24503+61c7c092.3
  • nginx-all-modules RHEL 8 1:1.24.0-3.module+el8.10.0+24503+61c7c092.3
  • nginx-mod-http-perl RHEL 8 1:1.24.0-3.module+el8.10.0+24503+61c7c092.3
  • nginx-mod-http-xslt-filter RHEL 8 1:1.24.0-3.module+el8.10.0+24503+61c7c092.3
  • nginx-mod-http-image-filter RHEL 8 1:1.24.0-3.module+el8.10.0+24503+61c7c092.3

red hat advisories RHSA-2026:38847RHSA-2026:36639RHSA-2026:36618RHSA-2026:36364RHSA-2026:36331RHSA-2026:27197

  • nginx SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +5 more 1.21.5-150400.3.25.1
  • nginx SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Server Applications 15 SP7 1.21.5-150600.10.24.1
  • nginx SLES 16.0, SLES for SAP applications 16.0 1.27.2-160000.6.1

suse advisories SUSE-SU-2026:3448-1SUSE-SU-2026:3329-1SUSE-SU-2026:22943-1SUSE-SU-2026:22951-1

  • nginx openSUSE Leap 16.0 1.27.2-160000.6.1
  • nginx openSUSE Tumbleweed 1.31.2-1.1

opensuse advisories openSUSE-SU-2026:21439-1openSUSE-SU-2026:11066-1

  • nginx AlmaLinux 8 1:1.24.0-3.module_el8.10.0+4215+c88f2fa5.3.alma.1
  • nginx-mod-mail AlmaLinux 8 1:1.24.0-3.module_el8.10.0+4215+c88f2fa5.3.alma.1
  • nginx-filesystem AlmaLinux 8 1:1.24.0-3.module_el8.10.0+4215+c88f2fa5.3.alma.1
  • nginx-mod-stream AlmaLinux 8 1:1.24.0-3.module_el8.10.0+4215+c88f2fa5.3.alma.1
  • nginx-all-modules AlmaLinux 8 1:1.24.0-3.module_el8.10.0+4215+c88f2fa5.3.alma.1
  • nginx-mod-http-perl AlmaLinux 8 1:1.24.0-3.module_el8.10.0+4215+c88f2fa5.3.alma.1
  • nginx-mod-http-xslt-filter AlmaLinux 8 1:1.24.0-3.module_el8.10.0+4215+c88f2fa5.3.alma.1
  • nginx-mod-http-image-filter AlmaLinux 8 1:1.24.0-3.module_el8.10.0+4215+c88f2fa5.3.alma.1

almalinux advisories ALSA-2026:38847ALSA-2026:36618ALSA-2026:36639ALSA-2026:36331ALSA-2026:36364

  • nginx Rocky Linux 9 2:1.20.1-28.el9_8.4.rocky.0.1
  • nginx Rocky Linux 8 1:1.24.0-3.module+el8.10.0+40144+38158758
  • nginx Rocky Linux 8 1:1.24.0-3.module+el8.10.0+40187+52bedf24.1
  • nginx Rocky Linux 8 1:1.24.0-3.module+el8.10.0+40220+e6a4bcb0.2
  • nginx Rocky Linux 9 2:1.26.3-9.module+el9.8.0+40222+e48d13b6.1
  • nginx Rocky Linux 9 2:1.26.3-9.module+el9.8.0+40194+40adfc1b
  • nginx Rocky Linux 10 2:1.26.3-6.el10_2.5
  • nginx Rocky Linux 9 1:1.24.0-7.module+el9.8.0+40193+7b2d11e4.1.rocky.0.1

rocky linux advisories RLSA-2026:36331RLSA-2026:38847RLSA-2026:36639RLSA-2026:36364RLSA-2026:36618

  • nginx Alpine 3.21 1.26.3-r2
  • nginx Alpine 3.23, Alpine 3.22 1.28.3-r4
  • nginx Alpine 3.24 1.30.3-r0

alpine advisories ALPINE-CVE-2026-42055

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • nginx Azure Linux 3.0 1.28.3-8

azure linux advisories AZL-91419

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-42055 updated cvss 8.1

nginx: NGINX: Arbitrary code execution or Denial of Service via heap-based buffer overflow with crafted HTTP/2 headers

  • Red Hat CodeReady Linux Builder EUS (v.9.6) nginx-debuginfo 1.20.1-22.el9_6.7, nginx-mod-devel 1.20.1-22.el9_6.7, nginx-debugsource 1.20.1-22.el9_6.7, nginx-core-debuginfo 1.20.1-22.el9_6.7, nginx-mod-mail-debuginfo 1.20.1-22.el9_6.7, nginx-mod-stream-debuginfo 1.20.1-22.el9_6.7, +3 more
    fixed: vendor fix RHSA-2026:93467
  • Red Hat Discovery 2 discovery/discovery-ui-rhel9 1784821750
    fixed: vendor fix RHSA-2026:46836
  • Red Hat Enterprise Linux AppStream (v. 8) nginx 1.24.0-3.module+el8.10.0+24503+61c7c092.3, nginx-mod-mail 1.24.0-3.module+el8.10.0+24503+61c7c092.3, nginx-filesystem 1.24.0-3.module+el8.10.0+24503+61c7c092.3, nginx-mod-stream 1.24.0-3.module+el8.10.0+24503+61c7c092.3, nginx-all-modules 1.24.0-3.module+el8.10.0+24503+61c7c092.3, nginx-mod-http-perl 1.24.0-3.module+el8.10.0+24503+61c7c092.3, +2 more
    fixed: vendor fix RHSA-2026:38847
  • Red Hat Enterprise Linux AppStream (v. 9) nginx 1.20.1-28.el9_8.4, nginx-core 1.20.1-28.el9_8.4, nginx-mod-mail 1.20.1-28.el9_8.4, nginx-filesystem 1.20.1-28.el9_8.4, nginx-mod-stream 1.20.1-28.el9_8.4, nginx-all-modules 1.20.1-28.el9_8.4, +21 more
    fixed: vendor fix RHSA-2026:36618
  • Red Hat Enterprise Linux AppStream (v. 10) nginx 1.26.3-6.el10_2.5, nginx-core 1.26.3-6.el10_2.5, nginx-mod-mail 1.26.3-6.el10_2.5, nginx-filesystem 1.26.3-6.el10_2.5, nginx-mod-stream 1.26.3-6.el10_2.5, nginx-all-modules 1.26.3-6.el10_2.5, +3 more
    fixed: vendor fix RHSA-2026:36364
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) nginx 1.20.1-14.el9_2.7, nginx-core 1.20.1-14.el9_2.7, nginx-mod-mail 1.20.1-14.el9_2.7, nginx-filesystem 1.20.1-14.el9_2.7, nginx-mod-stream 1.20.1-14.el9_2.7, nginx-all-modules 1.20.1-14.el9_2.7, +3 more
    fixed: vendor fix RHSA-2026:93472
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) nginx 1.20.1-16.el9_4.7, nginx-core 1.20.1-16.el9_4.7, nginx-mod-mail 1.20.1-16.el9_4.7, nginx-filesystem 1.20.1-16.el9_4.7, nginx-mod-stream 1.20.1-16.el9_4.7, nginx-all-modules 1.20.1-16.el9_4.7, +3 more
    fixed: vendor fix RHSA-2026:93468
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) nginx 1.20.1-22.el9_6.7, nginx-core 1.20.1-22.el9_6.7, nginx-mod-mail 1.20.1-22.el9_6.7, nginx-filesystem 1.20.1-22.el9_6.7, nginx-mod-stream 1.20.1-22.el9_6.7, nginx-all-modules 1.20.1-22.el9_6.7, +3 more
    fixed: vendor fix RHSA-2026:93467
show 6 more
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) nginx-debuginfo 1.20.1-28.el9_8.4, nginx-mod-devel 1.20.1-28.el9_8.4, nginx-debugsource 1.20.1-28.el9_8.4, nginx-core-debuginfo 1.20.1-28.el9_8.4, nginx-mod-mail-debuginfo 1.20.1-28.el9_8.4, nginx-mod-stream-debuginfo 1.20.1-28.el9_8.4, +3 more
    fixed: vendor fix RHSA-2026:36331
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) nginx-debuginfo 1.26.3-6.el10_2.5, nginx-mod-devel 1.26.3-6.el10_2.5, nginx-debugsource 1.26.3-6.el10_2.5, nginx-core-debuginfo 1.26.3-6.el10_2.5, nginx-mod-mail-debuginfo 1.26.3-6.el10_2.5, nginx-mod-stream-debuginfo 1.26.3-6.el10_2.5, +3 more
    fixed: vendor fix RHSA-2026:36364
  • Red Hat Hardened Images nginx 1.30.3-2.hum1, nginx-core 1.30.3-2.hum1, nginx-mod-mail 1.30.3-2.hum1, nginx-filesystem 1.30.3-2.hum1, nginx-mod-stream 1.30.3-2.hum1, nginx-all-modules 1.30.3-2.hum1, +5 more
    fixed: vendor fix RHSA-2026:27197
  • Red Hat Openshift Data Foundation 4.19 odf4/odf-console-rhel9 1793126829
    fixed: vendor fix RHSA-2026:92650
  • Red Hat Update Infrastructure 5 rhui5/cds-rhel9 1784794778, rhui5/rhua-rhel9 1784795076, rhui5/rhua-tp-rhel9 1787241260, rhui5/cds-kubernetes-rhel9 1784794818, rhui5/cds-kubernetes-tp-rhel9 1787241211
    fixed: vendor fix RHSA-2026:44481
  • Red Hat Discovery 2 discovery/discovery-server-rhel9 1784821670 Red Hat Openshift Data Foundation 4 odf4/ocs-client-console-rhel9, odf4/odf-multicluster-console-rhel9 Red Hat Openshift Data Foundation 4.19 odf4/cephcsi-rhel9 1793125678, odf4/odf-cli-rhel9 1793126086, odf4/mcg-core-rhel9 1793125866, odf4/mcg-rhel9-operator 1793125881, odf4/ocs-rhel9-operator 1793126016, odf4/odf-rhel9-operator 1793126364, +26 more Red Hat Update Infrastructure 5 rhui5/cds-tp-rhel9 1787241206, rhui5/haproxy-rhel9 1784795112, rhui5/installer-rhel9 1784794289, rhui5/installer-tp-rhel9 1787135742
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
4 mo ago

Exploit prediction

6.54% chance of exploitation in the next 30 days, higher than 93% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 4.0 9.2 CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CISA ADP 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 4.0 9.2 CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
bitnami nginx
>=1.30.0, <1.30.3
>=1.31.0, <1.31.2
1.30.3
1.31.2
bitnami nginx-gateway
>=1.30.0, <1.30.3
>=1.31.0, <1.31.2
1.30.3
1.31.2
bitnami nginx-gateway-fabric
>=1.3.0, <2.6.4
2.6.4

Affected products

  • F5 NGINX Open Source
  • F5 NGINX Plus
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Discovery 2
  • Red Hat Red Hat Hardened Images
  • Red Hat Red Hat Update Infrastructure 5
  • Red Hat Red Hat Openshift Data Foundation 4

Classification

Weakness
  • CWE-122 Heap-based Buffer Overflow
  • CWE-131 Incorrect Calculation of Buffer Size
  • CWE-787 Out-of-bounds Write
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.