Memory disclosure or worker restart via charset conversion
Published Jun 17, 2026 · Updated Jun 17, 2026
Out-of-bounds reads in F5 NGINX Open Source and NGINX Plus allow remote attackers to disclose worker memory or restart a worker. The ngx_http_charset_module conversion path reads beyond a heap buffer while decoding UTF-8 content into the configured destination charset. Exploitation is unauthenticated but requires a location with source_charset utf-8 and another charset directive, plus runtime conditions outside attacker control.
Summary
What happened
Out-of-bounds reads in F5 NGINX Open Source and NGINX Plus allow remote attackers to disclose worker memory or restart a worker. The ngx_http_charset_module conversion path reads beyond a heap buffer while decoding UTF-8 content into the configured destination charset. Exploitation is unauthenticated but requires a location with source_charset utf-8 and another charset directive, plus runtime conditions outside attacker control.
The record
- CVE
- CVE-2026-48142
- Published
- Jun 17, 2026
- Updated
- Jun 17, 2026
- Vendor
- F5 Networks
- Product
- NGINX Open Source
- Classifications
- CWE-125, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 17, 2026CVE publishedPublication date reported by the CVE source.
- Jun 17, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.13.10 <1.31.2
- Affected versionversion=1.30.0 <1.30.3
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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