Medium 6.6Published Jun 22, 2026

CVE-2026-54278AIOHTTP: Unread Compressed Request Bodies Bypass client_max_size During Cleanup

Updated under an hour ago (Oct 28, 2026, 1:23 AM ET)

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It affects aio-libs aiohttp and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for aio-libs aiohttp

Exploited in the last 30 days

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, during cleanup it is possible for a compressed request body to be decompressed into memory in one chunk. An attacker may be able to send a compressed payload in specific situations that could be decompressed into memory, potentially leading to DoS (a zip bomb edge case). This vulnerability is fixed in 3.14.1.

CVSS: 6.6 MEDIUM (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U
Weakness (CWE): CWE-409
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Jun 23, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

aio-libs aiohttp aio_libs:aiohttp (from the name)	before 3.14.1	CNA record
aiohttp aiohttp aiohttp:aiohttp	before 3.14.1	NVD

References

References

https://github.com/aio-libs/aiohttp/security/advisories/GHSA-g3cq-j2xw-wf74	x-refsource-confirm, third-party-advisory
https://github.com/aio-libs/aiohttp/commit/4f7480e474cccc6a8cc2c92ad3f17a31dedf8232	x-refsource-misc, patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.