CVE-2026-8168 — Denial-of-service vulnerability in the SVG parser and renderer impacts Qt
Uncontrolled recursion in the SVG parser and renderer of the Qt SVG module (QtSvg) in Qt Group Qt allows attackers to cause a denial of service (application crash via stack exhaustion) via a crafted SVG file with deeply nested elements.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.4% (30-day exploitation probability)+5
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Qt Qt).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Exploitation requires user interaction: tighten email/web filtering and warn affected users.
- Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.1 | CVSS 4.0 | High | — | — | a59d8014-47c4-4630-ab43-e1b13cbe58e3 via NIST National Vulnerability Database |
| 7.1 | CVSS 4.0 | High | — | — | Qt via CVE Program (cve.org) e CISA ADP |
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/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:X/R:X/V:X/RE:X/U:X (score shown at the top: a59d8014-47c4-4630-ab43-e1b13cbe58e3) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Track CPU/memory spikes and availability drops correlated with request patterns.
Timeline
What happened to this CVE, newest first.
- 2026
- Source status changed · Received → Awaiting Analysis
- SSVC assessment updated
- Affected products added · qt/qt
- Record published
- CVSS changed · 7.1
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 19, 2026 – Oct 19, 2026
References
11 on the record
- codereview.qt-project.org/c/qt/qtsvg/+/730591
- codereview.qt-project.org/c/qt/qtsvg/+/743488
- codereview.qt-project.org/c/qt/qtsvg/+/738811
- codereview.qt-project.org/c/qt/qtsvg/+/730892
- codereview.qt-project.org/c/qt/qtsvg/+/733245
- codereview.qt-project.org/c/qt/qtsvg/+/730501
- codereview.qt-project.org/c/qt/qtsvg/+/756512
- codereview.qt-project.org/c/qt/qtsvg/+/748966
- codereview.qt-project.org/c/qt/qtsvg/+/730590
- codereview.qt-project.org/c/qt/qtsvg/+/731257
- wiki.qt.io/List_of_known_vulnerabilities_in_Qt_products
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-105923 Null-pointer dereference in QTriangulator reachable through VectorImage 11h
- Medium CVE-2026-101201 QBinaryJson::fromBinaryData() integer overflow leading to OOB read 1d
- Medium CVE-2026-79680 Authentication bypass vulnerability in the password authentication mechanism of the Qt VNC Server module 27d
- Low CVE-2026-78253 Denial-of-service (stack-exhaustion) vulnerability in QXmlStreamReader::readElementText() impacts Qt 28d
- Low CVE-2026-79616 Out-of-bounds read vulnerability in Context2D.path and PathSvg.path properties impacts Qt Quick 28d
- Medium CVE-2026-76151 Out-of-bounds read (buffer over-read) vulnerability in HTTP Cache-Control response header parsing impacts Qt Framework (QtNetwork module) Sep 16, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-8168 is "Denial-of-service vulnerability in the SVG parser and renderer impacts Qt", rated High. It affects Qt (Qt); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.1 describes technical severity. EPSS 0.40% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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