CVE-2026-54277: aiohttp: C HTTP Parser Bypasses max_line_size for Fragmented Lines

June 15, 2026

It is possible to bypass the max_line_size check in parts of an HTTP request in the C parser.

References

github.com/advisories/GHSA-63hw-fmq6-xxg2
github.com/aio-libs/aiohttp/commit/5ab61bb4cd88f19b712f12c7c9295fe262bf804d
github.com/aio-libs/aiohttp/security/advisories/GHSA-63hw-fmq6-xxg2
nvd.nist.gov/vuln/detail/CVE-2026-54277

Code Behaviors & Features

Detect and mitigate CVE-2026-54277 with GitLab Dependency Scanning

Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Dependency Scanning using SBOM also detects vulnerabilities from proprietary advisories that this site does not include. Learn more about Dependency Scanning using SBOM →