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TI-2021-05939 Aliases CVE-2021-23158GHSA-hgcq-f5fx-5qp6

Double free in htmldoc

Priority MEDIUM 47CWE-415Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
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-415 and the CVSS impact.

Summary

A flaw was found in htmldoc in v1.9.12. Double-free in function pspdf_export(),in ps-pdf.cxx may result in a write-what-where condition, allowing an attacker to execute arbitrary code and denial of service.

Why it matters now

EPSS 0.02436 84th 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

VendorProductAffected versionsFixed inStatusSource
—htmldocAffects v1.9.12 and before.—No fix listedCNA
  • htmldoc Vendor— Affected Affects v1.9.12 and before. Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:htmldoc_project:htmldoc:1.9.12:*:*:*:*:*:*:*1.9.12VulnerableHtmldoc Project
  • cpe:2.3:a:htmldoc_project:htmldoc:1.9.12:*:*:*:*:*:*:* Versions 1.9.12 Vulnerable ·Htmldoc Project

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-23158
  2. 2026-10-03 Alias added: GHSA-hgcq-f5fx-5qp6

References

  • 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
See all 22 →

Sources