CVE-2026-103262

Tornado versions before 6.5.9 contain an unbounded memory accumulation vulnerability in CurlAsyncHTTPClient that allows remote attackers to cause denial of service by sending a compressed response. Attackers can send a gzip-encoded decompression bomb that accumulates in memory without size limits, causing the application process to be killed by out-of-memory conditions.

CVSS 4.0

8.7CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.6% chance of exploitation in the next 30 days; higher than 49% of CVEs (scores of 2026-10-25)

CWE

CWE-409

Published

2026-10-01

Modified

2026-10-06

Record from

the NVD, synced 2026-10-19

Packages (OSV)

References

• https://github.com/tornadoweb/tornado/commit/e412435febba4569c552c5c9054f1bf92bd171a9
• https://github.com/tornadoweb/tornado/security/advisories/GHSA-chx6-46f5-w4vp
• https://www.vulncheck.com/advisories/tornado-before-6.5.9-denial-of-service-via-curlasynchttpclient
• https://github.com/tornadoweb/tornado/security/advisories/GHSA-chx6-46f5-w4vp

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