Search/CVE-2026-84784
● CVE — High

CVE-2026-84784

VendoropensslProductopensslDiscoveredSep 29, 2026UpdatedOct 8, 2026

Issue summary: A malicious remote peer may flood the local QUIC stack with NEW_CONNECTION_ID frames by avoiding a limit check on how many connection IDs the remote QUIC stack can use. Impact summary: The local QUIC stack sends a RETIRE_CONN_ID frame for every NEW_CONNECTION_ID frame it receives. The RETIRE_CONN_ID frame is dispatched via the Control Frame Queue (CFQ). If the remote peer also withholds ACKs, then it can force the local stack to allocate ~400MB (depending on ACK delay). CWE: CWE-770: Allocation of Resources Without Limits or Throttling Description: RFC 9000 sections 5.1.1 and 5.1.2 [1] describe the mechanism by which a remote peer can notify the local QUIC stack to change the destination connection ID (a.k.a. CID) the local stack uses to identify the connection at the…

CVSS v3.1
7.5 HIGH
EPSS
0.40%
probability of exploitation in 30 days
CISA KEV
Not listed
no confirmed exploitation reported
News coverage
1
sources referencing this CVE
Related IOCs
0
seen in the same coverage
Intelligence Reports1
1 intelligence report available

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CVSS v3.1 Detail
Attack VectorNETWORK
Attack ComplexityLOW
Privileges RequiredNONE
User InteractionNONE
ScopeUNCHANGED
ConfidentialityNONE
IntegrityNONE
AvailabilityHIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Connections
4 relationships
Timeline
disclosure → media coverage
Sep 29, 2026
Disclosure — published as a CVE record. · last revised by NVD Oct 8, 2026
Sep 29, 2026
ubuntu.com reports: USN-8847-1: OpenSSL vulnerabilities