Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1336 CNY

100%

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

CVSS 5.3 · Medium EPSS 0.15% · P4

Possible ATT&CK Techniques 1AI

T1499 · Endpoint Denial of Service

Affected Version Matrix 1

VendorProductVersion RangeStatus
h2oquicly< dccf5d4affected
Get alerts for future matching vulnerabilitiesLog in to subscribe

I. Basic Information for CVE-2026-44434

Vulnerability Information

Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Quicly is vulnerable to stateless reset injection
Source: CVE Program / CVE List V5
Vulnerability Description
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 handshake is complete. Only packets that carry some secret patterns are considered as stateless resets. Quicly allows the peer to share up to 4 such patterns per connection. However, until now, it failed to determine which of the 4 slots that it uses to retain the secret patterns contains a valid entry. As the slots are zero-initialized, the failure meant that, unless the peer advertised 4 of such patterns, an all-zero pattern was treated as a stateless reset.In effect, this allowed an on-path attacker to reset QUIC connections governed by Quicly. This issue has been fixed by commit dccf5d4.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Source: CVE Program / CVE List V5
Vulnerability Type
对数据真实性的验证不充分
Source: CVE Program / CVE List V5
Vulnerability Title
H2O quicly 输入验证错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
H2O quicly是H2O公司开源的一个 IETF QUIC 协议的实现。 H2O quicly dccf5d4之前版本存在安全漏洞,该漏洞源于缺少数据包条目验证,可能导致路径攻击者重置QUIC连接。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

VendorProductAffected VersionsCPESubscribe
h2oquicly < dccf5d4 -

II. Public POCs for CVE-2026-44434

#POC DescriptionSource LinkShenlong Link
AI-Generated POCPremium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-44434

登录查看更多情报信息。

Patches & Fixes for CVE-2026-44434 (1)

Vendor Advisories for CVE-2026-44434 (1)

Same Patch Batch · h2o · 2026-07-16 · 7 CVEs total

CVE-2026-444367.5 HIGHQuicly is vulnerable to connection state corruption
CVE-2026-444357.5 HIGHQuicly: Remote Denial of Service via assertion failure when CRYPTO stream handshake data e
CVE-2026-444537.5 HIGHh2o is vulnerable to musl libc stack overflow
CVE-2026-543407.5 HIGHh2o has HTTP/2 state amplification
CVE-2026-444525.9 MEDIUMh2o is vulnerable to heap overrun
CVE-2026-444335.3 MEDIUMQuicly is vulnerable to memory exhaustion

IV. Related Vulnerabilities

V. Comments for CVE-2026-44434

No comments yet


Leave a comment