CVE-2026-42934

NGINX ngx_http_charset_module vulnerability

MEDIUM
4.8
CVSS Score
Published: May 13, 2026 at 02:12 PM UTC
Updated: October 26, 2026 at 02:10 PM UTC
7 products affected across 1 vendorNGINX PlusNGINX Open SourceNGINX Ingress Controller

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Severity
MEDIUM4.8
Exploit prediction
EPSS 0.7%
SSVC
No known exploit

Description

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_charset_module module. When charset, source_charset, and charset_map and proxy_pass with disabled buffering ("off") directives are configured, unauthenticated attackers can send requests that with conditions beyond the attackers' 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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4.3.0 ≤ v ≤ 4.7.04.8.0
1.3.0 ≤ v ≤ 1.6.22.0.0 ≤ v ≤ 2.6.0
3.5.0 ≤ v ≤ 3.7.24.0.0 ≤ v ≤ 4.0.15.0.0 ≤ v ≤ 5.4.2
2.16.0 ≤ v ≤ 2.22.0
0.3.50 ≤ v ≤ 0.9.71.0.0 ≤ v ≤ 1.30.00.3.50
Affected range stops below 1.30.1, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in 1.31.0 (unaffected)
r32 ≤ v ≤ r36R32R36
Affected range stops below R32 P6, so it looks safe — our inference, not a vendor statement
Affected range stops below R36 P4, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in R37 (unaffected)
4.9.0 ≤ v ≤ 4.16.05.1.0 ≤ v ≤ 5.8.05.9.0 ≤ v ≤ 5.12.1

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

Vendor AdvisoryPatchMitigation
Source: cverecord
https://my.f5.com/manage/s/article/K000161028

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.8MEDIUMf5
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusANALYZED
CWE
CWE-125

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