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VulnerabilityPublished Updated

CVE-2026-3909: Qtwebkit opensource src · security update

Affects Google qtwebkit-opensource-srcSource GCVE Database

0
Authoritative record:CVE-2026-3909· High 8.8

Exploited in the wild · KEV due 27 Mar 2026 · 2% EPSS : apply the vendor's fix or mitigations to Google qtwebkit-opensource-src now.

Data as of 28 Oct 2026, 05:11 UTC

CVSS 3.1 base score
8.8High
How severe the flaw is on the 0–10 CVSS scale.
KEV deadline
 US federal agencies must patch by this date; a sensible deadline for everyone else. Other KEV due dates
EPSS
2.3% chance of exploitation in 30 days – higher than 83% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

  1. Disclosed: evidence found.

    CVE published 12 Mar 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: evidence found.

    Listed in CISA KEV 1 day after disclosure

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

    No attack traffic recorded by OffSeq Mirage sensors

Timeline

  1. CVE ID reserved

    by Chrome

    , 45 hours before disclosure

  2. CVE published

    on cve.org

    , t = 0

  3. In Threat Radar

    record ingested

    , 14 minutes after disclosure

  4. , 1 day after disclosure

  5. KEV remediation due

    US federal deadline

    , 15 days after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Affected software

ProductAffectedFixed in
Ubuntu 26.10webkit2gtkpkg:deb/ubuntu/webkit2gtk?arch=source&distro=stonkingOther threatsAffected
  • 2.52.0-1 – 2.52.6-1ubuntu1
5 affected builds
Fixed in–
Ubuntu 26.04 LTSwebkit2gtkpkg:deb/ubuntu/webkit2gtk?arch=source&distro=resoluteOther threatsAffected
  • 2.48.6-1ubuntu2 – 2.52.6-0ubuntu0.26.04.1
12 affected builds
Fixed in–
Ubuntu 24.04 LTSqtwebkit-opensource-srcpkg:deb/ubuntu/qtwebkit-opensource-src?arch=source&distro=nobleOther threatsAffected
  • 5.212.0~alpha4-33 – 5.212.0~alpha4-36
6 affected builds
Fixed in–
Ubuntu 24.04 LTSwebkit2gtkpkg:deb/ubuntu/webkit2gtk?arch=source&distro=nobleOther threatsAffected
  • 2.42.1-2 – 2.52.6-0ubuntu0.24.04.1
26 affected builds
Fixed in–
Ubuntu 22.04 LTSqtwebkit-opensource-srcpkg:deb/ubuntu/qtwebkit-opensource-src?arch=source&distro=jammyOther threatsAffected
  • 5.212.0~alpha4-12 – 5.212.0~alpha4-15ubuntu1
6 affected builds
Fixed in–
Ubuntu 22.04 LTSwebkit2gtkpkg:deb/ubuntu/webkit2gtk?arch=source&distro=jammyOther threatsAffected
  • 2.34.0-1ubuntu1 – 2.50.4-0ubuntu0.22.04.1
42 affected builds
Fixed in–

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

Description

CVE-2026-3909 is a high severity security vulnerability affecting multiple specific versions of the QtWebKit open source component. It has a CVSS 3.1 base score of 8.8, indicating a critical impact on confidentiality, integrity, and availability. The vulnerability requires no privileges and can be exploited remotely with user interaction. A security update has been issued to address this flaw.

References

Community reviews

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