Buffer over-read in NGINX ngx_http_scgi_module and ngx_http_uwsgi_module
CVE-2026-42946 is a vulnerability in NGINX's ngx_http_scgi_module and ngx_http_uwsgi_module. When scgi_pass or uwsgi_pass is configured, a state mismatch after an incomplete upstream status-line read can lead to incorrect cross-buffer pointer subtraction during response parsing. Reported consequences include excessive memory allocation with an attacker-influenced key length of roughly 1 TB and buffer over-read behavior. An unauthenticated attacker who can act as a man-in-the-middle and control responses from the upstream SCGI/uWSGI server may trigger the flaw, causing the NGINX worker process to read memory out of bounds or terminate and restart.
Are you exposed to this one?
Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.
Impact, mitigation & remediation
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
If you can’t patch tonight, do this now.
Remediation
Patch, then assume compromise.
Exploits
No valid public exploits. Mallory filtered out 3 candidates as fakes, detection scripts, or README-only repos.
All candidate exploits were filtered out by Mallory's validation.
Affected products & vendors
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
14 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A high-severity excessive memory allocation vulnerability in NGINX ngx_http_scgi_module and ngx_http_uwsgi_module that can crash worker processes.
An excessive memory allocation flaw in NGINX ngx_http_scgi_module and ngx_http_uwsgi_module that could let an adversary-in-the-middle controlling upstream responses read worker memory or force a restart.
An excessive memory allocation vulnerability in NGINX ngx_http_scgi_module and ngx_http_uwsgi_module that may allow memory disclosure or worker process restart under specific upstream-response control conditions.
An excessive memory allocation flaw in NGINX SCGI/UWSGI modules that can crash worker processes via extremely large allocations.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.