Allocation of Resources Without Limits or Throttling Affecting openssl package, versions [3.4.0,]
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published26 Aug 2026
- disclosed25 Aug 2026
- creditOpal Wright (Trail of Bits)
Introduced: 25 Aug 2026
NewCVE-2026-63075 (opens in a new tab)How to fix?
A fix was pushed into the master branch but not yet published.
Overview
Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling unbounded resource growth due to ossl_ackm_on_tx_packet in ssl/quic/quic_ackm.c and txp_pkt_commit in ssl/quic/quic_txp.c. A remote peer can exhaust memory by completing a QUIC handshake and then repeatedly sending ack-eliciting traffic, such as PING frames, while withholding acknowledgments for ACK-only responses. The QUIC transmit path records ACK-only packets in the normal packet history even though they are not ack-eliciting, so the connection retains ACK-only metadata for its lifetime. With sustained traffic or many concurrent connections, this connection-scoped state growth can lead to denial of service through memory exhaustion.