High severity · published Jun 22, 2026
CVE-2026-54278
AIOHTTP: Unread Compressed Request Bodies Bypass client_max_size During Cleanup
7.5
CVSS
0.5%
EPSS
No
On KEV
Description
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 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 42% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AI
aiohttp · aio-libs
< 3.14.1 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-54278
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-54278
Patch
https://github.com/aio-libs/aiohttp/commit/4f7480e474cccc6a8cc2c92ad3f17a31dedf8232
Third Party Advisory
https://github.com/aio-libs/aiohttp/security/advisories/GHSA-g3cq-j2xw-wf74
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