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HIGH

CVE-2026-49853

CVSS v3

7.7

HIGH

EPSS Score

0.5 %

exploit probability, as of 2026-10-19

CISA KEV

No

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
  • python3-tornadoAlmaLinux:10all versions · fixed in 6.5.8-0.el10_2.1
  • python3-tornadoAlmaLinux:9all versions · fixed in 6.5.8-0.el9_8.1

Vendor advisories

  • CVE-2026-49853 Red Hat Product Security39 products fixed · 8 known affected

    tornado: Tornado: Information disclosure via improper handling of credentials during HTTP redirects

    keylime as a component of Red Hat Enterprise Linux 9 · keylime-base as a component of Red Hat Enterprise Linux 9 · keylime-registrar as a component of Red Hat Enterprise Linux 9

  • RHSA-2026:80741 Red Hat Product Security13 products fixed

    Red Hat Security Advisory: python-tornado security update

  • RHSA-2026:67146 Red Hat Product Security13 products fixed

    Red Hat Security Advisory: python-tornado security update

  • RHSA-2026:67147 Red Hat Product Security13 products fixed

    Red Hat Security Advisory: python-tornado security update

Full record on NVD

Description

Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, SimpleAsyncHTTPClient shallow-copied redirected requests and removed only the Host header, leaving Authorization, auth_username, auth_password, and auth_mode in place when a redirect changed scheme, host, or port. This issue is fixed in version 6.5.6.

Technical details

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

Frequently asked questions

What is CVE-2026-49853?

Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, SimpleAsyncHTTPClient shallow-copied redirected requests and removed only the Host header, leaving Authorization, auth_username, auth_password, and auth_mode in place when a redirect changed scheme, host, or port. This issue is fixed in version 6.5.6.

Is CVE-2026-49853 actively exploited?

Active exploitation of CVE-2026-49853 has not been confirmed. Its EPSS score was 0.5% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-49853?

CVE-2026-49853 has a CVSS v3 base score of 7.7 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N.

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