Medium severity · published May 13, 2026
CVE-2026-42934
NGINX ngx_http_charset_module vulnerability
4.8
CVSS
0.7%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
None
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 54% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NO
NGINX Open Source · F5
0.3.50 before 1.30.1 · source: vendor, NVD
NP
NGINX Plus · F5
R36 before R36 P4; R32 before R32 P6 · source: vendor, NVD
DO
Dos · F5
4.3.0 through 4.7.0; 4.8.0 · source: NVD
NG
Nginx Gateway Fabric · F5
1.3.0 through 1.6.2; 2.0.0 through 2.6.0 · source: NVD
NI
Nginx Ingress Controller · F5
3.5.0 through 3.7.2; 4.0.0 through 4.0.1; 5.0.0 through 5.4.2 · source: NVD
NI
Nginx Instance Manager · F5
2.16.0 through 2.22.0 · source: NVD
WA
Waf · F5
4.9.0 through 4.16.0; 5.1.0 through 5.8.0; 5.9.0 through 5.12.1 · source: NVD
Affected product
NO
NGINX Open Source
F5
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