Skip to content
Noroxi
CVE-2026-48142· NVD / CVE Program· CNA f5

NGINX ngx_http_charset_module vulnerability

Noroxi assessment

Priority: Monitor (action score 25/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.37% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: azl3 nginx 1.28.3-5 on Azure Linux 3.0 1.28.3-6; azl3 nginx 1.28.3-6 on Azure Linux 3.0 1.28.3-6.

Low priority for now. Upgrade to azl3 nginx 1.28.3-5 on Azure Linux 3.0 1.28.3-6; azl3 nginx 1.28.3-6 on Azure Linux 3.0 1.28.3-6 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

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_charset_module module. When content is served or proxied through a location block with both source_charset utf-8; and a charset directive (for example, charset koi8-r;) configured, remote, unauthenticated attackers can send requests (in conjunction with conditions beyond their control) to cause a heap buffer over-read in the NGINX worker process, leading to limited disclosure of memory or a restart. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

MediumCVSS 6.3 · v4.0—No exploit Fix available
Published
Jun 17, 2026
Updated
Aug 11, 2026
EPSS
0.3% · 29th percentile

Report tools

JSON

Action score

25

Monitor

Low priority for now.

CVSS
25 / 40 · 6.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · f5
4.8
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L

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
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-48142

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for f5 records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

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 help

Affected 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.

VendorProduct
f5dos
f5nginx gateway fabric
f5nginx ingress controller
f5nginx instance manager
f5nginx open source
f5nginx plus
f5waf

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • f5 nginx open source1.0.0 and later · up to 1.30.2 inclusive
  • f5 nginx open source1.31.0 and later · up to 1.31.1 inclusive
  • f5 nginx plus37.0.0.1 and later · before 37.0.2.1
  • f5 nginx plusr33 and later · before r36
  • f5 nginx plusr36

Versions reported by the vendor

Affected version ranges reported by the assigning authority (f5). Independent of NVD's CPE analysis and usually ahead of it.

  • F5 NGINX Open Source

    • 1.13.10 and later · before 1.31.2affected
    • 1.30.0 and later · before 1.30.3affected

  • F5 NGINX Plus

    • 37.0 and later · before 37.0.2.1affected
    • R36 and later · before R36 P6affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Alpine:v3.21nginxbefore 1.26.3-r21.26.3-r2
Alpine:v3.22nginxbefore 1.28.3-r41.28.3-r4
Alpine:v3.24nginxbefore 1.30.3-r01.30.3-r0
Debian:12nginxbefore 1.22.1-9+deb12u91.22.1-9+deb12u9
Debian:13nginxbefore 1.26.3-3+deb13u71.26.3-3+deb13u7
Debian:14nginxbefore 1.30.1-51.30.1-5
openSUSE:Leap 16.0nginxbefore 1.27.2-160000.6.11.27.2-160000.6.1
openSUSE:Tumbleweednginxbefore 1.31.2-1.11.31.2-1.1
Red Hat:hummingbird:1nginxbefore 0:1.30.3-2.hum10:1.30.3-2.hum1
Red Hat:hummingbird:1nginx-all-modulesbefore 0:1.30.3-2.hum10:1.30.3-2.hum1
Red Hat:hummingbird:1nginx-corebefore 0:1.30.3-2.hum10:1.30.3-2.hum1
Red Hat:hummingbird:1nginx-filesystembefore 0:1.30.3-2.hum10:1.30.3-2.hum1
Red Hat:hummingbird:1nginx-mod-develbefore 0:1.30.3-2.hum10:1.30.3-2.hum1
Red Hat:hummingbird:1nginx-mod-http-geoipbefore 0:1.30.3-2.hum10:1.30.3-2.hum1
Red Hat:hummingbird:1nginx-mod-http-image-filterbefore 0:1.30.3-2.hum10:1.30.3-2.hum1
Red Hat:hummingbird:1nginx-mod-http-perlbefore 0:1.30.3-2.hum10:1.30.3-2.hum1
Red Hat:hummingbird:1nginx-mod-http-xslt-filterbefore 0:1.30.3-2.hum10:1.30.3-2.hum1
Red Hat:hummingbird:1nginx-mod-mailbefore 0:1.30.3-2.hum10:1.30.3-2.hum1
Red Hat:hummingbird:1nginx-mod-streambefore 0:1.30.3-2.hum10:1.30.3-2.hum1
Red Hat:hummingbird:1nginx-mod-stream-geoipbefore 0:1.30.3-2.hum10:1.30.3-2.hum1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSnginxbefore 1.21.5-150400.3.25.11.21.5-150400.3.25.1
SUSE:Linux Enterprise Module for Server Applications 15 SP7nginxbefore 1.21.5-150600.10.24.11.21.5-150600.10.24.1
SUSE:Linux Enterprise Server 16.0nginxbefore 1.27.2-160000.6.11.27.2-160000.6.1

Same product

f5: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-42055NGINX ngx_http_proxy_v2_module and ngx_http_grpc_module vulnerability
    38Monitor
  • CVE-2026-42945NGINX ngx_http_rewrite_module vulnerability
    37Monitor
  • CVE-2026-42946NGINX ngx_http_scgi_module and ngx_http_uwsgi_module vulnerability
    33Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-40460May 13, 2026 · NGINX ngx_quic_module vulnerability
    27Monitor
  • ← EarlierCVE-2026-40701May 13, 2026 · NGINX ngx_http_ssl_module vulnerability
    25Monitor
  • ← EarlierCVE-2026-42934May 13, 2026 · NGINX ngx_http_charset_module vulnerability
    25Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
azl3 nginx 1.28.3-5 on Azure Linux 3.01.28.3-6 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 nginx 1.28.3-6 on Azure Linux 3.01.28.3-6 · CBL-Mariner ReleasesMicrosoft (MSRC)
alpine:nginx1.26.3-r2 · Alpine:v3.21Package registry (OSV)
debian:nginx1.22.1-9+deb12u9 · Debian:12Package registry (OSV)
opensuse:nginx1.31.2-1.1 · openSUSE:TumbleweedPackage registry (OSV)
red hat:nginx0:1.30.3-2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nginx-all-modules0:1.30.3-2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nginx-core0:1.30.3-2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nginx-filesystem0:1.30.3-2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nginx-mod-devel0:1.30.3-2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nginx-mod-http-geoip0:1.30.3-2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nginx-mod-http-image-filter0:1.30.3-2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nginx-mod-http-perl0:1.30.3-2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nginx-mod-http-xslt-filter0:1.30.3-2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nginx-mod-mail0:1.30.3-2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nginx-mod-stream0:1.30.3-2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:nginx-mod-stream-geoip0:1.30.3-2.hum1 · Red Hat:hummingbird:1Package registry (OSV)
suse:nginx1.27.2-160000.6.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

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.

No dated events beyond publication.

EPSS, last 120 days

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 researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-4293435 days apartNGINX ngx_http_charset_module vulnerability
    25Monitor

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).

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.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-125 · Out-of-bounds Read

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records