Heap Buffer Over-read in NGINX ngx_http_charset_module
CVE-2026-48142 is a heap buffer over-read vulnerability in NGINX Open Source and NGINX Plus affecting ngx_http_charset_module. The issue is triggered when content is served or proxied through a location block configured with both "source_charset utf-8;" and a "charset" directive, and decoding occurs through the charset_map path. A remote, unauthenticated attacker can send requests that, together with application-controlled conditions outside the attacker’s direct control, cause NGINX to process a specially crafted UTF-8 response body and read past the end of a heap buffer in the worker process. The flaw is an over-read rather than an overflow, and the vulnerable behavior occurs during UTF-8 decoding and charset conversion in ngx_http_charset_module.
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Exploits
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Recent activity
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A low-severity heap buffer over-read in NGINX charset conversion handling that can disclose limited worker process memory and could aid exploit chains by providing an information leak.
A low-severity heap buffer over-read in ngx_http_charset_module that can disclose limited worker process memory during crafted charset decoding.
A medium-severity vulnerability in the NGINX ngx_http_charset_module that could impact application behavior or degrade service reliability.
A medium-severity nginx vulnerability in ngx_http_charset_module involving specially crafted UTF-8 input and charset conversion handling.
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Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
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Cross-references every affected SKU, including bundled OEM variants.
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