MEDIUM

CVE-2026-49854

CVSS v3

5.3

MEDIUM

EPSS Score

0.4 %

exploit probability, as of 2026-10-19

CISA KEV

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

tornadoPyPIall versions · fixed in 6.5.6

Vendor advisories

CVE-2026-49854 Red Hat Product Security59 known affected
tornado: Tornado: Information disclosure via out-of-bounds read in websocket_mask
exploit-intelligence-tech-preview/vulnerability-analysis-rhel9 as a component of Exploit Intelligence · external-secrets-operator/bitwarden-sdk-server-rhel9 as a component of External Secrets Operator for Red Hat OpenShift · external-secrets-operator/external-secrets-operator-bundle as a component of External Secrets Operator for Red Hat OpenShift

Full record on NVD

Description

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.

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Published: 2026-07-14
Last Modified: 2026-07-15

Frequently asked questions

What is CVE-2026-49854?

Is CVE-2026-49854 actively exploited?

Active exploitation of CVE-2026-49854 has not been confirmed. Its EPSS score was 0.4% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-49854?

CVE-2026-49854 has a CVSS v3 base score of 5.3 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

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