CVE-2026-124040: critical vulnerability in civetweb
CivetWeb through 1.16 HTTP/2 Use-After-Free via Stale Pseudo-Header State
Published · Updated
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48Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 9.2epss 0.5%
from disclosure to weapon2 days
Published on NVDNov 6
1st PoC+2d
CivetWeb through 1.16, when built with USE_HTTP2 and enable_http2 on, contains a use-after-free vulnerability in handle_http2() that retains freed :method and :path pointers. Unauthenticated remote attackers can send a later HEADERS frame omitting these pseudo-headers to influence request method or path seen by access rules, or crash the server.
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Affected products
civetweb · civetwebpublic PoCs found — 1
githubgithub.com/zeetee1235/CVE-2026-124040★ 0⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
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