Medium severity · published Apr 3, 2026
CVE-2026-35536
In Tornado before 6.5.5, cookie attribute injection could occur because the domain, path, and samesite arguments to .RequestHandler.set_cookie were not checked for crafted…
5.3
CVSS
0.2%
EPSS
No
On KEV
Description
In Tornado before 6.5.5, cookie attribute injection could occur because the domain, path, and samesite arguments to .RequestHandler.set_cookie were not checked for crafted characters.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 15% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
TO
Tornado · tornadoweb
before 6.5.5 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-35536
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-35536
Product
https://github.com/tornadoweb/tornado/releases/tag/v6.5.5
Vendor Advisory
https://github.com/tornadoweb/tornado/security/advisories/GHSA-78cv-mqj4-43f7
More from Tornado
7.7
CVE-2026-49853
Tornado: Authorization header forwarded across cross-origin redirects in SimpleAsyncHTTPClient
7.5
CVE-2026-103262
Tornado before 6.5.9 Denial of Service via CurlAsyncHTTPClient
7.5
CVE-2026-91990
Tornado before 6.5.8 Memory Amplification DoS via multipart
7.5
CVE-2024-14029
Tornado before 6.4.1 HTTP Request Smuggling via Transfer-Encoding
7.5
CVE-2023-54397
Tornado before 6.3.3 HTTP Request Smuggling via Content-Length