Skip to main content
VulnerabilityPublished

CVE-2026-76151: qt · Out-of-bounds Read

Affects qtSource CVE Database V5

0
Compare

Not known to be exploited · CVSS 4.6 Medium : upgrade to 6.11.2 or 6.8.9 when convenient.

Data as of 31 Oct 2026, 08:20 UTC

CVSS 4.0 base score
4.6Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.6% chance of exploitation in 30 days – higher than 51% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 6.11.2, 6.8.9
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

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 16 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

What to do

Upgrade qt and org.qtproject/qt to 6.11.2 or 6.8.9.

Affected software

ProductAffectedFixed in
qtqtAffected
  • >=6.9.0 <6.11.2
Fixed in
  • 6.11.2
qtqtAffected
  • >=6.0.0 <6.8.9
Fixed in
  • 6.8.9
Mavenorg.qtproject/qtpkg:maven/org.qtproject/qtOther threatsAffected
  • >=6.0.0 <6.8.9
  • >=6.9.0 <6.11.2
Fixed in
  • 6.8.9
  • 6.11.2

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

If you cannot patch yet, avoid connecting to untrusted or potentially compromised HTTP servers that may send maliciously large Cache-Control headers. Consider applying application-level input validation or limiting header sizes if possible.

Description

CVE-2026-76151 is an out-of-bounds read vulnerability in the HTTP Cache-Control response header parsing within the QtNetwork module of Qt versions 6.0.0 through 6.8.8 and 6.9.0 through 6.11.1. This flaw allows remote attackers to cause a denial of service (application crash) by sending an excessively large Cache-Control header value from an untrusted or compromised HTTP server to a client application using QNetworkAccessManager. The issue affects only the client side, does not impact 32-bit builds, and involves read-only out-of-bounds access without information disclosure or code execution.

References

Community reviews

Loading reviews…