NULL pointer dereference in htmldoc
Priority LOW 36CWE-476Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-476.
Summary
A security issue was found in htmldoc v1.9.12 and before. A NULL pointer dereference in the function image_load_jpeg() in image.cxx may result in denial of service.
Why it matters now
EPSS 0.011 65th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | htmldoc | Fixed in htmldoc v1.9.12 and later. | — | No fix listed | CNA |
- htmldoc Vendor— Affected Fixed in htmldoc v1.9.12 and later. Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:htmldoc_project:htmldoc:*:*:*:*:*:*:*:* | up to 1.9.12 | Vulnerable | Htmldoc Project |
- cpe:2.3:a:htmldoc_project:htmldoc:*:*:*:*:*:*:*:* Versions up to 1.9.12 Vulnerable ·Htmldoc Project
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2021-23191
- 2026-10-03 Alias added: GHSA-rh6g-g88g-qmfg
References
More Htmldoc Project Htmldoc vulnerabilities
- TI-2024-30988 HTMLDOC v1.9.18 contains a buffer overflow in parse_pre function,ps-pdf.cxx:5681. CVSS 3.1CRITICAL 9.8
- TI-2024-30543 HTMLDOC before 1.9.19 has an out-of-bounds write in parse_paragraph in ps-pdf.cxx because… CVSS 3.1CRITICAL 9.8
- TI-2021-13278 An Out of Bounds flaw was discovered in htmodoc 1.9.12 in function parse_tree() in… CVSS 3.1HIGH 7.8
- TI-2021-13277 A flaw was discovered in htmodoc 1.9.12 in function parse_paragraph in ps-pdf.cxx ,this… CVSS 3.1HIGH 7.8
- TI-2022-00080 Memory corruption in michaelrsweet htmldoc CVSS 3.1HIGH 7.5
- TI-2021-05943 Heap-based buffer overflow in htmldoc CVSS 3.1CRITICAL 9.8
Sources
- CVE-2021-23191 · CVE Program
- CVE-2021-23191 · NVD
- FIRST EPSS
- GHSA-rh6g-g88g-qmfg · GitHub Advisory Database · CC BY 4.0
- CVE-2021-23191 · Red Hat security data · CC BY 4.0
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