CVE-2026-76151: qt · Out-of-bounds Read
Affects qtSource CVE Database V5
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
- 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:AExploitation evidence
Disclosed: evidence found.
CVE published 16 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
| Product | Affected | Fixed in |
|---|---|---|
| qtqt | Affected
| Fixed in
|
| qtqt | Affected
| Fixed in
|
Mavenorg.qtproject/qtpkg:maven/org.qtproject/qtOther threats | Affected
| Fixed in
|
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.