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Fencer Vulns
medium 4.6

CVE-2026-76151 json

Out-of-bounds read (buffer over-read) vulnerability in HTTP Cache-Control response header parsing impacts Qt Framework (QtNetwork module)

published 2026-09-16 53 d ago modified 2026-09-18 51 d ago also EUVD-2026-80385

cvss
4.6
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 52%
public exploits
0
none known

Summary

Out-of-bounds read (buffer over-read) in the HTTP Cache-Control response header parsing in the QtNetwork module in Qt Group Qt 6.0.0 through 6.8.8, and 6.9.0 through 6.11.1, allows remote attackers to cause a denial of service (application crash) via an excessively large Cache-Control header value returned by an untrusted or compromised HTTP server to an application using QNetworkAccessManager. Only the client side of the connection is affected and 32-bit builds are not affected; the out-of-bounds access is read-only, with no information disclosure and no code execution.

Patch / fix

  • qt qt 6.8.9, 6.11.2
  • qt6-base Debian 14 6.11.2+dfsg-5

debian advisories DEBIAN-CVE-2026-76151

  • AusweisApp openSUSE Tumbleweed 2.6.0-1.1

opensuse advisories openSUSE-SU-2026:12071-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-76151 updated cvss 7.5

qt5-qtbase: qt6-qtbase: qt: Denial of Service via excessively large HTTP Cache-Control header

  • Red Hat Enterprise Linux 10 qt6-qtbase
    affected: no fix available
  • Red Hat Hardened Images qt6-qtbase 6.11.2-3.1.hum1, qt5-qtbase 5.15.18-5.3.hum1, qt6-qtbase-gui 6.11.2-3.1.hum1, qt5-qtbase-gui 5.15.18-5.3.hum1, qt5-qtbase-tds 5.15.18-5.3.hum1, qt6-qtbase-odbc 6.11.2-3.1.hum1, +11 more
    fixed: vendor fix RHSA-2026:82734
  • Red Hat Enterprise Linux 7 qt5-qtbase, qt5-qtbase-gui, qt5-rpm-macros, qt5-qtbase-odbc, qt5-qtbase-mysql, qt5-qtbase-common, +2 more Red Hat Enterprise Linux 8 qt5-qtbase, qt5-qtbase-gui, qt5-qtbase-odbc, qt5-qtbase-mysql, qt5-qtbase-common, qt5-qtbase-examples, +1 more Red Hat Enterprise Linux 9 qt5-qtbase, qt5-qtbase-gui, qt5-qtbase-odbc, qt5-qtbase-mysql, qt5-qtbase-common, qt5-qtbase-examples, +1 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
53 d ago

Exploit prediction

0.67% chance of exploitation in the next 30 days, higher than 52% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 4.6 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/AU:N/R:A
CNA 4.0 4.6 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:N/R:A/V:X/RE:X/U:X

Affected products

  • qt qt

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.