Medium [CVE-2026-49854] Information disclosure via out-of-bounds read in websocket_mask
This medium-severity Red Hat Linux advisory covers CVE-2026-49854 affecting Exploit Intelligence, External Secrets Operator for Red Hat OpenShift, Lightspeed Core.
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Summary
Tornado is a Python web framework and asynchronous networking library.
Prior to 6.5.6, the optional native extension tornado.speedups implemented websocket_mask without validating that the mask argument is exactly four bytes, allowing the C function to read up to three bytes beyond the provided buffer when reached through Tornado XSRF token decoding with the native extension active. This issue is fixed in version 6.5.6.
This allowed the C function to read beyond the intended buffer, potentially exposing up to three bytes of uninitialized memory. This vulnerability can be triggered when the native extension is active and Tornado's Cross-Site Request Forgery (XSRF) token decoder is in use, leading to information disclosure.
This Moderate vulnerability in the Tornado web framework's optional native extension, `tornado.speedups`, could lead to information disclosure. When the native extension is active and the XSRF token decoder is in use, an out-of-bounds read of up to three bytes of uninitialized memory may occur.
This limited data exposure is contingent on specific configurations and does not directly lead to broader system compromise. Red Hat severity: Moderate — CVSS 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N).
Weakness: CWE-125.
- < 6.5.6
Official advisory · high-confidence parse· fetched 2 days ago·verify at source
Mitigation
Upgrade to a fixed release: 6.5.6. That is the remediation for this advisory.
The vendor advisory may list interim mitigations or workarounds not captured here. Review it before change work.
Official advisory · high-confidence parse· fetched 2 days ago·verify at source
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