Description
Tornado before 6.5.8 contains an incomplete fix for cookie attribute injection that allows attackers to inject arbitrary cookie attributes by passing capitalized or legacy keyword arguments to set_cookie. Attackers can embed semicolon-delimited data in capitalized parameters like Domain, Path, or SameSite to bypass validation and modify cookie security attributes.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| tornadoweb | tornado | 6.5.5 – < 6.5.8 | 6.5.8 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | python-tornado | No fix yet | — |
| Debian 12 | python-tornado | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | python-tornado | No fix yet | — |
| Ubuntu 26.04 LTS | python-tornado | No fix yet | — |
| Ubuntu 24.04 LTS | python-tornado | No fix yet | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 22.04 LTS | python-tornado | No fix yet | — |
| Ubuntu Pro 20.04 LTS | python-tornado | No fix yet | — |
| Ubuntu Pro 18.04 LTS | python-tornado | No fix yet | — |
| Ubuntu Pro 16.04 LTS | python-tornado | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | python-tornado | 4.5.3-150000.3.31.1 | SUSE-SU-2026:4404-1 |
| SLES 15 SP6 | python-tornado | 4.5.3-150000.3.31.1 | SUSE-SU-2026:4404-1 |
| SLES 15 SP6 | python-tornado6 | 6.3.2-150400.9.27.1 | SUSE-SU-2026:4403-1 |
| SLES 15 SP5 | python-tornado | 4.5.3-150000.3.31.1 | SUSE-SU-2026:4404-1 |
| SLES 15 SP5 | python-tornado6 | 6.3.2-150400.9.27.1 | SUSE-SU-2026:4403-1 |
| SLES 15 SP4 | python-tornado | 4.5.3-150000.3.31.1 | SUSE-SU-2026:4404-1 |
| SLES 15 SP4 | python-tornado6 | 6.3.2-150400.9.27.1 | SUSE-SU-2026:4403-1 |
| SLES 3 | python-tornado6 | 6.3.2-150400.9.27.1 | SUSE-SU-2026:4403-1 |
Show 11 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | python-tornado6 | 6.5-160000.7.1 | SUSE-SU-2026:24207-1 |
| SLES for SAP 15 SP6 | python-tornado | 4.5.3-150000.3.31.1 | SUSE-SU-2026:4404-1 |
| SLES for SAP 15 SP6 | python-tornado6 | 6.3.2-150400.9.27.1 | SUSE-SU-2026:4403-1 |
| SLES for SAP 15 SP5 | python-tornado | 4.5.3-150000.3.31.1 | SUSE-SU-2026:4404-1 |
| SLES for SAP 15 SP5 | python-tornado6 | 6.3.2-150400.9.27.1 | SUSE-SU-2026:4403-1 |
| SLES for SAP 15 SP4 | python-tornado | 4.5.3-150000.3.31.1 | SUSE-SU-2026:4404-1 |
| SLES for SAP 15 SP4 | python-tornado6 | 6.3.2-150400.9.27.1 | SUSE-SU-2026:4403-1 |
| SLES 16.0 | python-tornado6 | 6.5-160000.7.1 | SUSE-SU-2026:24207-1 |
| SLE Micro 6.2 | python-tornado6 | 6.5-160000.7.1 | SUSE-SU-2026:24121-1 |
| SLE Micro 5.5 | python-tornado | 4.5.3-150000.3.31.1 | SUSE-SU-2026:4404-1 |
| SLE Micro 5.4 | python-tornado | 4.5.3-150000.3.31.1 | SUSE-SU-2026:4404-1 |
| SLE Micro 5.3 | python-tornado | 4.5.3-150000.3.31.1 | SUSE-SU-2026:4404-1 |
| SLE HPC 15 SP5 | python-tornado | 4.5.3-150000.3.31.1 | SUSE-SU-2026:4404-1 |
| SLE HPC 15 SP5 | python-tornado6 | 6.3.2-150400.9.27.1 | SUSE-SU-2026:4403-1 |
| SLE HPC 15 SP4 | python-tornado | 4.5.3-150000.3.31.1 | SUSE-SU-2026:4404-1 |
| SLE HPC 15 SP4 | python-tornado6 | 6.3.2-150400.9.27.1 | SUSE-SU-2026:4403-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | python-tornado6 | 6.5-160000.7.1 | openSUSE-SU-2026:22059-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | tornado | >= 6.5.5, < 6.5.8 | 6.5.8 | GHSA-wwv5-g3v4-889x |
Advisories 5
- SUSE-SU-2026:24207-1 Security update for python-tornado6 SUSE / openSUSE Security Updates · Oct 21, 2026
- openSUSE-SU-2026:22059-1 Security update for python-tornado6 SUSE / openSUSE Security Updates · Oct 19, 2026
- SUSE-SU-2026:24121-1 Security update for python-tornado6 SUSE / openSUSE Security Updates · Oct 13, 2026
- SUSE-SU-2026:4403-1 Security update for python-tornado6 SUSE / openSUSE Security Updates · Oct 1, 2026
- SUSE-SU-2026:4404-1 Security update for python-tornado SUSE / openSUSE Security Updates · Oct 1, 2026
References
- GitHub Security Advisory (GHSA-wwv5-g3v4-889x) vendor-advisory
- VulnCheck Advisory: Tornado before 6.5.8 Cookie Attribute Injection via Capitalized kwargs third-party-advisory