StackPrism

PyPI package

tornado 4.4.2 vulnerabilities, and the version that fixes all of them

tornado 4.4.2 has 20 known vulnerabilities (10 rated high or critical); 6.5.9 fixes all of them.

PyPI (opens in a new tab) describes it as “Tornado is a Python web framework and asynchronous networking library, originally developed at FriendFeed.”

Known vulnerabilities
20
10 rated high or critical
Released
Sep 30, 2016
Latest is 6.5.10
Licence
Apache-2.0
Dependencies
None
Resolved by deps.dev

What to upgrade to

6.5.9 is the closest release with no known vulnerabilities.

  • 4.5.3

    Newest 4.x release. Released Jan 6, 2018.

    20 known vulnerabilities, worst rated warning

  • 6.5.9Upgrade to this

    Fixes all 20 known vulnerabilities. Released Sep 14, 2026.

    No known vulnerabilities

  • 6.5.10

    Latest release. Released Sep 15, 2026.

    No known vulnerabilities

6.5.9 came out on Sep 14, 2026. A coding agent trained before then doesn’t know it exists, so it may suggest an older release. AI knowledge cutoff dates

Hand the fix to your coding agent

One task with the upgrade, the file to change and why. Paste it into Claude Code, Cursor or Codex.

Findings

Every advisory for tornado 4.4.2

Known exploited first (CISA KEV), then by how likely they are to be exploited (FIRST EPSS), then by severity. Each id links to its OSV.dev record.

  1. WarningCVE-2023-28370 on OSV.dev (opens in a new tab)GHSA-hj3f-6gcp-jg8jEPSS: top 34%

    Open redirect in Tornado

    Fixed in 6.3.2. Published May 25, 2023.

  2. CriticalCVE-2024-52804 on OSV.dev (opens in a new tab)GHSA-8w49-h785-mj3cEPSS: top 37%

    Tornado has an HTTP cookie parsing DoS vulnerability

    Fixed in 6.4.2. Published Nov 22, 2024.

  3. CriticalCVE-2025-47287 on OSV.dev (opens in a new tab)GHSA-7cx3-6m66-7c5mEPSS: top 47%

    Tornado vulnerable to excessive logging caused by malformed multipart form data

    Fixed in 6.5. Published May 16, 2025.

  4. CriticalCVE-2026-49855 on OSV.dev (opens in a new tab)GHSA-mgf9-4vpg-hj56EPSS: top 52%

    tornado AsyncHTTPClient accumulates decompressed chunks without size limit (gzip bomb)

    Fixed in 6.5.6. Published Jun 15, 2026.

  5. CriticalCVE-2025-67725 on OSV.dev (opens in a new tab)GHSA-c98p-7wgm-6p64EPSS: top 55%

    Tornado: Quadratic DoS via Repeated Header Coalescing

    Fixed in 6.5.3. Published Jul 20, 2026.

  6. CriticalCVE-2025-67726 on OSV.dev (opens in a new tab)GHSA-jhmp-mqwm-3gq8EPSS: top 57%

    Tornado: Quadratic DoS via Crafted Multipart Parameters

    Fixed in 6.5.3. Published Jul 20, 2026.

  7. CriticalCVE-2026-103262 on OSV.dev (opens in a new tab)GHSA-chx6-46f5-w4vpEPSS: top 57%

    tornado: CurlAsyncHTTPClient enforces no response-size limit — decompression bomb drives unbounded memory accumulation to OOM

    Fixed in 6.5.9. Published Sep 30, 2026.

  8. CriticalCVE-2026-103263 on OSV.dev (opens in a new tab)GHSA-c2m8-h5v5-343rEPSS: top 57%

    Tornado: StaticFileHandler follows symlinks outside static root (path traversal)

    Fixed in 6.5.9. Published Sep 30, 2026.

  9. CriticalCVE-2026-31958 on OSV.dev (opens in a new tab)GHSA-qjxf-f2mg-c6mcEPSS: top 59%

    Tornado is vulnerable to DoS due to too many multipart parts

    Fixed in 6.5.5. Published Mar 12, 2026.

  10. WarningCVE-2026-103261 on OSV.dev (opens in a new tab)GHSA-3hv7-mjh2-fv65EPSS: top 61%

    Tornado: Unbounded query-string argument count allows event-loop-stalling DoS

    Fixed in 6.5.9. Published Sep 30, 2026.

  11. CriticalCVE-2026-49853 on OSV.dev (opens in a new tab)GHSA-3x9g-8vmp-wqvfEPSS: top 63%

    Tornado: Authorization header forwarded across cross-origin redirects in SimpleAsyncHTTPClient

    Fixed in 6.5.6. Published Jun 15, 2026.

  12. WarningCVE-2026-91990 on OSV.dev (opens in a new tab)GHSA-8423-8fgw-73vqEPSS: top 65%

    tornado: multipart split() creates huge temp list before max_parts check -> memory amplification DoS (httputil.py:34)

    Fixed in 6.5.8. Published Sep 1, 2026.

  13. LowCVE-2026-49854 on OSV.dev (opens in a new tab)GHSA-cx3h-4qpv-8hc9EPSS: top 66%

    Tornado has out-of-bounds memory access via C extension

    Fixed in 6.5.6. Published Jun 12, 2026.

  14. WarningCVE-2023-54397 on OSV.dev (opens in a new tab)GHSA-qppv-j76h-2rpxEPSS: top 70%

    Tornado vulnerable to HTTP request smuggling via improper parsing of `Content-Length` fields and chunk lengths

    Fixed in 6.3.3. Published Aug 14, 2023.

  15. WarningCVE-2024-14029 on OSV.dev (opens in a new tab)GHSA-753j-mpmx-qq6gEPSS: top 73%

    Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') in tornado

    Fixed in 6.4.1. Published Jun 6, 2024.

  16. CriticalCVE-2026-82397 on OSV.dev (opens in a new tab)GHSA-mpf4-983q-p7j4EPSS: top 74%

    Tornado: Urlencoded body parsing omits max_num_fields, so one request can stall the event loop

    Fixed in 6.5.8. Published Sep 2, 2026.

  17. WarningCVE-2026-35536 on OSV.dev (opens in a new tab)GHSA-78cv-mqj4-43f7EPSS: top 81%

    Tornado has incomplete validation of cookie attributes

    Fixed in 6.5.5. Published Mar 11, 2026.

  18. WarningCVE-2026-91992 on OSV.dev (opens in a new tab)GHSA-pw6j-qg29-8w7fEPSS: top 84%

    Tornado: CurlAsyncHTTPClient leaks per-request credentials on handle reuse

    Fixed in 6.5.7. Published Jun 15, 2026.

  19. WarningCVE-2024-58384 on OSV.dev (opens in a new tab)GHSA-w235-7p84-xx57EPSS: top 85%

    Tornado has a CRLF injection in CurlAsyncHTTPClient headers

    Fixed in 6.4.1. Published Jun 6, 2024.

  20. WarningCVE-2025-67724 on OSV.dev (opens in a new tab)GHSA-pr2v-jx2c-wg9fEPSS: top 86%

    Tornado vulnerable to Header Injection and XSS via reason argument

    Fixed in 6.5.3. Published Jul 20, 2026.

Is tornado the only one?

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How this page is checked

StackPrism asks OSV.dev which advisories affect exactly tornado 4.4.2, merges duplicates filed under several ids, and ranks them with CISA’s Known Exploited Vulnerabilities list and FIRST EPSS. Release dates and deprecation come from deps.dev and PyPI. No AI writes this page: every sentence comes from that data, refreshed every few hours.

Last checked against PyPI, OSV.dev, deps.dev, CISA KEV and FIRST EPSS.