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Fencer Vulns
high 8.1

CVE-2026-42530 json

NGINX Open-Source ngx_http_v3_module vulnerability

published 2026-06-17 4 mo ago modified 2026-10-26 13 d ago also BIT-nginx-2026-42530 , BIT-nginx-gateway-2026-42530 , EUVD-2026-37717

cvss
8.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
6.2%
EPSS 6.2% chance of exploitation in 30 days, percentile 93%
public exploits
0
none known

Summary

NGINX Open Source has a vulnerability in the ngx_http_v3_module module. When NGINX Open Source is configured to use the HTTP/3 QUIC module, a remote unauthenticated attacker along with conditions beyond their control can use a specially crafted HTTP/3 session to reopen a QPACK encoder stream. This may cause a Use-after-Free 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 1.31.2
  • bitnami nginx-gateway 1.31.2
  • F5 NGINX Open Source 1.31.2
  • Red Hat Red Hat Hardened Images 1.30.2-1.hum1
  • nginx hummingbird 1 1.30.2-1.hum1
  • nginx-core hummingbird 1 1.30.2-1.hum1
  • nginx-mod-mail hummingbird 1 1.30.2-1.hum1
  • nginx-filesystem hummingbird 1 1.30.2-1.hum1
  • nginx-mod-stream hummingbird 1 1.30.2-1.hum1
  • nginx-all-modules hummingbird 1 1.30.2-1.hum1
  • nginx-mod-http-perl hummingbird 1 1.30.2-1.hum1
  • nginx-mod-http-geoip hummingbird 1 1.30.2-1.hum1

red hat advisories RHSA-2026:20351

  • nginx openSUSE Tumbleweed 1.31.2-1.1

opensuse advisories openSUSE-SU-2026:11066-1

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-2026-42530 updated cvss 8.1

nginx: ngx_http_v3_module: use-after-free issue leads to denial of service

  • Red Hat Hardened Images nginx 1.30.2-1.hum1, nginx-core 1.30.2-1.hum1, nginx-mod-mail 1.30.2-1.hum1, nginx-filesystem 1.30.2-1.hum1, nginx-mod-stream 1.30.2-1.hum1, nginx-all-modules 1.30.2-1.hum1, +5 more
    fixed: vendor fix “To mitigate this vulnerability, disable HTTP/3 by removing quic from all listen directives.” RHSA-2026:20351
  • Red Hat Enterprise Linux 8 nginx, nginx-mod-mail, nginx-filesystem, nginx-mod-stream, nginx-all-modules, nginx-mod-http-perl, +2 more Red Hat Enterprise Linux 9 nginx, nginx-core, nginx-mod-mail, nginx-filesystem, nginx-mod-stream, nginx-all-modules, +3 more Red Hat Enterprise Linux 10 nginx Red Hat Lightspeed proxy 1 insights-proxy/insights-proxy-container-rhel9
    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

6.22% 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:N/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:N/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
>=1.31.0, <1.31.2
1.31.2
bitnami nginx-gateway
>=1.31.0, <1.31.2
1.31.2

Affected products

  • F5 NGINX Open Source
  • Red Hat Red Hat Hardened Images
  • 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 Lightspeed proxy 1

Classification

Weakness
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.