CVE-2026-103262: tornadoweb tornado
Vulnerability summary
CVE-2026-103262 is a high (CVSS 8.7) vulnerability in tornadoweb tornado. EPSS estimates a 0.53% chance of exploitation in the next 30 days, higher than 43.3% of scored vulnerabilities.
Timeline
- 01-10-2026PublishedVulnerability first disclosed.
- 06-10-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
9 scores · 6 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- OSV · DebianEcosystem advisory · calculated8.7HighCVSS: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
- NVDNIST8.7HighCVSS: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
- OSV · PypiEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · Red hatEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.53%
Chance of exploitation in the next 30 days
Percentile
43%
Versus all other CVEs
30-day change
Change unavailable
Change unavailable
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Redhat4 products
- python-tornado< 0:6.5.10-1.el9_8.1 | < 0:6.5.10-1.el10_2.1
- python-tornado-debugsource< 0:6.5.10-1.el9_8.1 | < 0:6.5.10-1.el10_2.1
- python3-tornado< 0:6.5.10-1.el9_8.1 | < 0:6.5.10-1.el10_2.1
- python3-tornado-debuginfo< 0:6.5.10-1.el9_8.1 | < 0:6.5.10-1.el10_2.1
Debian1 product
- python-tornadoAll versions (No fix recorded)
PyPI1 product
- tornado< 6.5.9
Tornadoweb1 product
- tornado< 6.5.9
Ubuntu1 product
- python-tornadoAll versions (No fix recorded)
5 vendors · 8 products
References
20 links- github.com/tornadoweb/tornado/security/advisories/GHSA-chx6-46f5-w4vpVendor AdvisoryWEBREPORTARTICLE
- www.vulncheck.com/advisories/tornado-before-6.5.9-denial-of-service-via-curlasynchttpclientThird Party AdvisoryREPORTARTICLE
