CVE•Published 2026-10-08•Modified 2026-10-09•1 article on news•3 live references•NVD data
CVE-2026-78663
Vulnerability data via NVD (ingested)
CVSS v3.1
9.1
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
EPSS percentile
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Description
The HTTP/2 server can refund connection-level flow control twice for the same data: Once when a client resets a stream (refunding data for any sent-but-unread portion of the stream), and again when a request handler reads the buffered data. A malicious client can exploit this to bypass the configured connection-level flow control limit (MaxReceiveBufferPerConnection). Total buffered data is still limited by the concurrent stream limit and stream-level flow control.
Timeline
Published 2026-10-08
Modified 2026-10-09
External references
Search for exposed instances
Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).
More intel sources (5)
Shodan report
vuln:CVE-2026-78663Country / ASN / product breakdown for the vuln query.
Censys
vulnerabilities.cve_id: CVE-2026-78663Censys host search filtered to this CVE id.
grep.app
CVE-2026-78663Public source-code mentions — fast PoC discovery.
GitHub code
CVE-2026-78663GitHub code search for direct mentions.
Google dork
"CVE-2026-78663" exploit -site:nvd.nist.govWrite-ups and news, NVD excluded.