CVE-2026-103262

Tornado before 6.5.9 Denial of Service via CurlAsyncHTTPClient

HIGH 8.7

At a glance

Source: NVD
EPSS: EPSS 0.63 % · percentile 50 (2026-10-28)
State: PUBLISHED
Published: 2026-10-01 10:42 UTC
Updated: 2026-10-06 00:08 UTC
Assigner: VulnCheck
NVD status: Deferred

Description

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.

Weaknesses (CWE)

CWE-409 — Improper Handling of Highly Compressed Data (Zip Bomb)

References

Scores

Version	Score	Vector	Scored by
CVSS 4.0	HIGH 8.7	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	VulnCheck
CVSS 3.1	HIGH 7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	VulnCheck
CVSS 4.0	HIGH 8.7	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:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X	NVD · disclosure@vulncheck.com (Secondary)
CVSS 3.1	HIGH 7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	NVD · disclosure@vulncheck.com (Secondary)

Advisories

GHSA-chx6-46f5-w4vp — tornado: CurlAsyncHTTPClient enforces no response-size limit — decompression bomb drives unbounded memory accumulation to OOM

European references

ENISA EUVD · EUVD-2026-90656
GCVE · GCVE-0-2026-103262

Affected products

Product	Versions
tornadoweb · tornado	affected 0 < 6.5.9 ; unaffected 6.5.9

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD