{"id":"DEBIAN-CVE-2026-63075","details":"Issue summary: When OpenSSL processes QUIC traffic from a peer that repeatedly sends ack-eliciting packets while not acknowledging ACK-only responses, the QUIC stack can retain ACK-only packet metadata for the lifetime of the connection.  Impact summary: A remote peer that can complete a QUIC handshake can cause connection-scoped memory growth which may lead to Denial of Service through memory exhaustion, especially with sustained traffic or many concurrent QUIC connections.  CWE: CWE-770: Allocation of Resources Without Limits or Throttling  Description: When the OpenSSL QUIC stack sends an ACK-only packet, there is no requirement by the QUIC protocol that the peer will acknowledge that ACK-only packet (i.e. it is itself not ack-eliciting). However, the OpenSSL implementation stores the metadata about the ACK frames regardless. In and of itself that's ok, but if a malicious peer establishes a connection, and then drives the connection such that ACK-only packets are forced from the  OpenSSL implementation peer (i.e., by sending numerous PING frames), and then withholding any subsequent acks for ack-eliciting data, like legitimate data, said malicious peer can force inappropriate memory growth on the OpenSSL peer, potentially leading to a Denial of Service.  The fix is to ensure that we account for the transmission of the ACK-only packet in the packet histories high and low watermark without actually storing the ACK-only packet metadata itself.  FIPS impact: no The OpenSSL FIPS module is not affected as the QUIC code is outside the FIPS module boundary.","modified":"2026-09-13T16:00:06.537291050Z","published":"2026-08-25T13:19:26.413Z","upstream":["CVE-2026-63075"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-63075"}],"affected":[{"package":{"name":"openssl","ecosystem":"Debian:13","purl":"pkg:deb/debian/openssl?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.5.7-1~deb13u2"}]}],"versions":["3.5.1-1","3.5.1-1+deb13u1","3.5.2-1","3.5.3-1","3.5.4-1","3.5.4-1~deb13u1","3.5.4-1~deb13u2","3.5.5-1","3.5.5-1~deb13u1","3.5.5-1~deb13u2","3.5.6-1~deb13u1","3.5.6-1~deb13u2","3.5.7-1~deb13u1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-63075.json"}},{"package":{"name":"openssl","ecosystem":"Debian:14","purl":"pkg:deb/debian/openssl?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.6.4-1"}]}],"versions":["3.5.1-1","3.5.2-1","3.5.3-1","3.5.4-1","3.5.4-1~deb13u1","3.5.4-1~deb13u2","3.5.5-1","3.5.5-1~deb13u1","3.5.5-1~deb13u2","3.5.6-1~deb13u1","3.5.6-1~deb13u2","3.5.7-1~deb13u1","3.5.7-1~deb13u2","3.6.0-1","3.6.0-2","3.6.0~~alpha1-1","3.6.0~~beta1-1","3.6.1-1","3.6.1-2","3.6.1-3","3.6.2-1","3.6.3-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-63075.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}