What is CVE-2026-103262?

CVE-2026-103262 is a high-severity vulnerability in Tornadoweb Tornado, classified under Improper Handling of Highly Compressed Data (Data Amplification). CVSS score: 7.5/10. Published 2026-10-01.

How severe is CVE-2026-103262?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Tornadoweb Tornado

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.

Published 2026-10-01 · last modified 2026-10-01.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Tornadoweb Tornado

Weakness classification (CWE)

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

References

github.com/tornadoweb/tornado/security/advisories/GHSA-chx6-46f5-w4vp (vendor-advisory)
github.com/tornadoweb/tornado/commit/e412435febba4569c552c5c9054f1bf92bd171a9 (patch)
www.vulncheck.com/advisories/tornado-before-6.5.9-denial-of-service-via-curlasy… (third-party-advisory)

Frequently asked questions

What is CVE-2026-103262?: CVE-2026-103262 is a high-severity vulnerability in Tornadoweb Tornado, classified under Improper Handling of Highly Compressed Data (Data Amplification). CVSS score: 7.5/10. Published 2026-10-01.
How severe is CVE-2026-103262?: High severity. CVSS v3 base score is 7.5 out of 10.