CVE-2026-44436

Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP server. Prior to commit 8b178e6, Quicly is vulnerable to a Denial of Service attack through connection state corruption. In QUIC Invariants, the maximum length of a Connection ID is 255 bytes, while QUIC...

CVE-2026-44434

Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP server. Prior to commit dccf5d4, Quicly was vulnerable to stateless reset injection through lack of packet entry validation. The QUIC protocol is designed to withstand packet injection attacks, once the...

CVE-2026-44433

Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP server. Prior to commit 8b178e6, an adversarial peer could send a STREAM frame carrying just one byte at the largest offset being permitted to obtain additional flow control credit, which under certain...

CVE-2026-44436 Quicly is vulnerable to connection state corruption

Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP server. Prior to commit 8b178e6, Quicly is vulnerable to a Denial of Service attack through connection state corruption. In QUIC Invariants, the maximum length of a Connection ID is 255 bytes, while QUIC...

CVE-2026-44436 Quicly is vulnerable to connection state corruption

Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP server. Prior to commit 8b178e6, Quicly is vulnerable to a Denial of Service attack through connection state corruption. In QUIC Invariants, the maximum length of a Connection ID is 255 bytes, while QUIC...

CVE-2026-44436

Quicly (QUIC implementation used with H2O) is vulnerable to a Denial of Service due to connection state corruption caused by a 255-byte Connection ID handling in the decoder, while QUIC version 1 requires a 20-byte CID buffer. The library lacked enforcement for 20-byte CIDs, allowing mismatched I...

CVE-2026-44435

CVE-2026-44435 : Quicly (QUIC protocol implementation used with H2O) contains an assertion failure that triggers a Denial of Service when the total number of valid handshake messages over a CRYPTO stream within a single packet number space exceeds 32KB. The issue is fixed by commit 937d0e9. Affec...

CVE-2026-44435

Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP server. Prior to commit 937d0e9, an assertion failure is raised when the total number of valid handshake messages received over a CRYPTO stream of a single packet number space exceeds 32KB, causing a...

CVE-2026-44435 Quicly: Remote Denial of Service via assertion failure when CRYPTO stream handshake data exceeds 32KB

Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP server. Prior to commit 937d0e9, an assertion failure is raised when the total number of valid handshake messages received over a CRYPTO stream of a single packet number space exceeds 32KB, causing a...

CVE-2026-44435 Quicly: Remote Denial of Service via assertion failure when CRYPTO stream handshake data exceeds 32KB

Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP server. Prior to commit 937d0e9, an assertion failure is raised when the total number of valid handshake messages received over a CRYPTO stream of a single packet number space exceeds 32KB, causing a...

CVE-2026-44434

Quicly (QUIC protocol implementation used with H2O HTTP server) was vulnerable to stateless reset injection before commit dccf5d4 due to lack of packet entry validation, allowing an on-path attacker to reset QUIC connections by exploiting zero-initialized secret-pattern slots. The issue has been ...

CVE-2026-44434 Quicly is vulnerable to stateless reset injection

Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP server. Prior to commit dccf5d4, Quicly was vulnerable to stateless reset injection through lack of packet entry validation. The QUIC protocol is designed to withstand packet injection attacks, once the...

CVE-2026-44433 Quicly is vulnerable to memory exhaustion

Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP server. Prior to commit 8b178e6, an adversarial peer could send a STREAM frame carrying just one byte at the largest offset being permitted to obtain additional flow control credit, which under certain...

CVE-2026-44433

Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP server. Prior to commit 8b178e6, an adversarial peer could send a STREAM frame carrying just one byte at the largest offset being permitted to obtain additional flow control credit, which under certain...

PT-2026-60600

Name of the Vulnerable Software and Affected Versions Quicly versions prior to commit dccf5d4 Description Quicly, an IETF QUIC protocol implementation used in the H2O HTTP server, is susceptible to stateless reset injection. The issue stems from a lack of packet entry validation when handling...

CVE-2025-61684

Quicly, an IETF QUIC protocol implementation, is susceptible to a denial-of-service attack prior to commit d9d3df6a8530a102b57d840e39b0311ce5c9e14e. A remote attacker can exploit these bugs to trigger an assertion failure that crashes process using Quicly. Commit...

CVE-2025-61684

Quicly, an IETF QUIC protocol implementation, is susceptible to a denial-of-service attack prior to commit d9d3df6a8530a102b57d840e39b0311ce5c9e14e. A remote attacker can exploit these bugs to trigger an assertion failure that crashes process using Quicly. Commit...

CVE-2025-61684

Quicly, an IETF QUIC protocol implementation, is susceptible to a denial-of-service attack prior to commit d9d3df6a8530a102b57d840e39b0311ce5c9e14e. A remote attacker can exploit these bugs to trigger an assertion failure that crashes process using Quicly. Commit...

CVE-2025-61684 Quicly has assertion failures

Quicly, an IETF QUIC protocol implementation, is susceptible to a denial-of-service attack prior to commit d9d3df6a8530a102b57d840e39b0311ce5c9e14e. A remote attacker can exploit these bugs to trigger an assertion failure that crashes process using Quicly. Commit...

CVE-2025-61684

CVE-2025-61684 affects Quicly, an IETF QUIC protocol implementation. The vulnerability is a denial-of-service caused by an assertion failure that crashes the process, exploitable before commit d9d3df6a8530a102b57d840e39b0311ce5c9e14e. The issue is mitigated by the mentioned commit which fixes the...