CVE-2026-498557.5HighCWE-409
tornado AsyncHTTPClient accumulates decompressed chunks without size limit (gzip bomb)
tornadoweb · tornado
Not in CISA KEV
0.6%probability of exploitation in the next 30 days
47th percentile
050100
Higher than 47% of scored CVEs
7.5HighCVSS 3.1
LowMediumHighCrit.
DescriptionNVD
Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, Tornado gzip decompression routines processed limited-size chunks but did not enforce an overall limit on accumulated decompressed chunks, allowing a malicious server accessed by SimpleAsyncHTTPClient or an HTTPServer configured with decompress_request=True to consume effectively unlimited memory. This issue is fixed in version 6.5.6.
Coverage1 article · 1 outlet
First in our coverage: SecurityOnline, 16 Jun.
- Tornado fixes credential leak in redirect, urges immediate updateSecurityOnline · first in our coverage · mentions it in passing
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