Denial-of-Service Vulnerability in quic-go's HTTP/3 Client and Server Implementations
CVE-2026-40898

5.3MEDIUM

Key Information:

Vendor

Quic-go

Status
Quic-go
Vendor
CVE Published:
4 June 2026

What is CVE-2026-40898?

An attacker can exploit quic-go's HTTP/3 implementations prior to version 0.59.1 by sending a specially crafted QPACK-encoded HEADERS frame. This can lead to excessive memory allocation in both clients and servers, due to the implementation failing to enforce limits on the size of the decoded trailer field section. This can result in denial-of-service conditions, as resource exhaustion and potential crashes may occur. Version 0.59.1 addresses this issue by imposing limits on the decoded field section size, thus enhancing the overall security of the implementation.

Affected Version(s)

quic-go < 0.59.1

References

https://github.com/quic-go/quic-go/security/advisories/GH...
x_refsource_CONFIRM
https://github.com/quic-go/quic-go/releases/tag/v0.59.1
x_refsource_MISC

CVSS V3.1

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.