CVE-2026-84784 OpenSSL - Allocation of Resources Without Limits or Throttling

OpenSSL QUIC stack contains an allocation of resources without limits caused by improper handling of NEW_CONNECTION_ID and RETIRE_CONNECTION_ID frames, letting remote attackers flood the stack and cause excessive memory allocation, exploit requires sending crafted QUIC frames without ACKs.

CVSS base score 7.5 /10
High
CISA KEV
Not listed
Public exploit
None known
EPSS
0.40% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Allocation of Resources Without Limits or Throttling
Impact
Denial Of Service
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
29 September 2026
Updated
15 October 2026
Weakness
CWE-770

Vendor fix

Update to the latest OpenSSL version with corrected QUIC connection ID retirement logic.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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