CVE-2026-54277
highpriority · track · 30EPSS 0.006 · 47 %ileEUFRRUUSEPSS · scored 2026-10-27
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, it is possible to bypass the max_line_size check in parts of an HTTP request in the C parser. If using the optimised C parser (the default in pre-built wheels), then an attacker may be able to send oversized lines through the HTTP parser and use an excessive amount of memory, potentially leading to DoS. This vulnerability is fixed in 3.14.1.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.6–7.5
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (12)
Products and version ranges known to be affected.
advisories (3)
Vendor and ecosystem advisories describing this.
- GHSA-63hw-fmq6-xxg2aiohttp: C HTTP Parser Bypasses max_line_size for Fragmented Lines2026-06-15ghsa · osvUS
### Summary It is possible to bypass the max_line_size check in parts of an HTTP request in the C parser. ### Impact If using the optimised C parser (the default in pre-built wheels), then an attacker may be able to send oversized lines through the HTTP parser and use an excessive amount of memory, potentially leading to DoS. ----- Patch: https://github.com/aio-libs/aiohttp/commit/5ab61bb4cd88f19b712f12c7c9295fe262bf804d
- CERTFR-2026-AVI-1385Multiples vulnérabilités dans les produits VMwareFrançais2026-10-26vendor · certfrFR
- PYSEC-2026-21102026-06-22vendor · osvUS
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, it is possible to bypass the max_line_size check in parts of an HTTP request in the C parser. If using the optimised C parser (the default in pre-built wheels), then an attacker may be able to send oversized lines through the HTTP parser and use an excessive amount of memory, potentially leading to DoS. This vulnerability is fixed in 3.14.1.
also known as (7)
Other names and identifiers for this entity.
sources
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references (6)
External citations — patches, advisories, analysis.
- https://github.com/aio-libs/aiohttp/commit/5ab61bb4cd88f19b712f12c7c9295fe262bf804dcnnvd
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-63hw-fmq6-xxg2cnnvd
- https://github.com/aio-libs/aiohttp/commit/5ab61bb4cd88f19b712f12c7c9295fe262bf804denisa_euvd
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-63hw-fmq6-xxg2enisa_euvd
- https://github.com/aio-libs/aiohttp/commit/5ab61bb4cd88f19b712f12c7c9295fe262bf804dPatchnvd
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-63hw-fmq6-xxg2Vendor Advisorynvd
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