{"apiVersion":"1.0","identifier":"CVE-2026-63075","description":"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.","publishedAt":"2026-08-25T13:19:26","lastModifiedAt":"2026-08-25T15:16:36","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-63075","cvssScore":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","epssProbability":0.0048,"riskScore":0.78,"affectedProduct":"OpenSSL","affectedVersions":"unknown","vulnerabilityType":"Library","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-63075","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-63075","en":"https://www.redsauce.net/en/cves/CVE-2026-63075","fr":"https://www.redsauce.net/fr/cves/CVE-2026-63075","pt":"https://www.redsauce.net/pt/cves/CVE-2026-63075","de":"https://www.redsauce.net/de/cves/CVE-2026-63075","sk":"https://www.redsauce.net/sk/cves/CVE-2026-63075","el":"https://www.redsauce.net/el/cves/CVE-2026-63075"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-63075"}}