Buffer overflow in QTextMarkdownImporter
There is a Heap-based Buffer Overflow vulnerability in QTextMarkdownImporter. This requires an incorrectly formatted markdown file to be passed to QTextMarkdownImporter to trigger the overflow. This issue affects Qt from 6.8.0 to 6.8.4. Versions up to 6.6.0 are known to be unaffected, and the fix is in 6.8.4 and later.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for help- Published
- Apr 11, 2025
- Updated
- Jul 29, 2026
- EPSS
- 0.2% · 12th percentile
- CWE
- CWE-122
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Report tools
Action score
19
Monitor
Low priority for now.
- CVSS
- 19 / 40 · 4.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · TQtC
- 4.8
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/U:Clear
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (TQtC). Independent of NVD's CPE analysis and usually ahead of it.
Qt Qt
- 6.8.4not affected
- before 6.6.0not affected · python
- 6.6.0 and later · before 6.8.0unknown · python
- 6.8.0 and later · before 6.8.4affected · python
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:13 | qt6-base | before 6.8.2+dfsg-6 | 6.8.2+dfsg-6 |
Same product
qt: all recordsOther highest-scoring records for the same primary product.
- CVE-2020-12267setMarkdown in Qt before 5.14.2 has a use-after-free related to QTextMarkdownImporter::insertBlock.40Plan
- CVE-2018-19873An issue was discovered in Qt before 5.11.3.40Plan
- CVE-2017-10904Qt for Android prior to 5.9.0 allows remote attackers to execute arbitrary OS commands via unspecified vectors.40Plan
- CVE-2024-36048QAbstractOAuth in Qt Network Authorization in Qt before 5.15.17, 6.x before 6.2.13, 6.3.x through 6.5.x before 6.5.6, and 6.6.x through 6.7.39Monitor
- CVE-2023-51714An issue was discovered in the HTTP2 implementation in Qt before 5.15.17, 6.x before 6.2.11, 6.3.x through 6.5.x before 6.5.4, and 6.6.x bef39Monitor
- CVE-2011-3194Buffer overflow in the TIFF reader in gui/image/qtiffhandler.cpp in Qt 4.7.4 allows remote attackers to cause a denial of service (crash) an39Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Qt Qt | 6.8.4 | Vendor (CNA) |
| debian:qt6-base | 6.8.2+dfsg-6 · Debian:13 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- oss-fuzzfinder
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-6210390 days apartType confusion and heap-buffer-overflow in Qt SVG marker handling causing application crash34Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- No account or password is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- P
- Scope
- X
Weakness class (CWE)
CWE-122 · Heap-based Buffer OverflowCVSS vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/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:Clear
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- codereview.qt-project.org/c/qt/qtbase/+/635546
- www.openwall.com/lists/oss-security/2025/04/24/4
- www.openwall.com/lists/oss-security/2025/04/24/5
- www.openwall.com/lists/oss-security/2025/04/24/6
- www.openwall.com/lists/oss-security/2025/04/25/1
- www.openwall.com/lists/oss-security/2025/04/25/2
Vendor advisories and official records. Exploit/PoC links are deliberately left out.