CVE-2026-54278
aiohttp: Unread Compressed Request Bodies Bypass client_max_size During Cleanup
Description
### Summary During cleanup it is possible for a compressed request body to be decompressed into memory in one chunk. ### Impact 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). ### Workaround Disable compression if unable to upgrade. ----- Patch: https://github.com/aio-libs/aiohttp/commit/4f7480e474cccc6a8cc2c92ad3f17a31dedf8232
How to fix CVE-2026-54278
To remediate CVE-2026-54278, upgrade the affected package to a fixed version below.
- PyPI/aiohttp—upgrade to 3.14.1 or later
Is CVE-2026-54278 being exploited?
No exploitation signal available. Neither CISA KEV nor a current EPSS score has been published for CVE-2026-54278.
Affected packages (1)
- from 0, < 3.14.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | 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 |