How severe is CVE-2021-26259?

CVE-2021-26259 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-26259 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (63rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-26259?

CVE-2021-26259 affects Htmldoc Project Htmldoc. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-26259?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-26259 published?

CVE-2021-26259 was published on 2022-03-03 and last updated on 2026-06-17.

CVE-2021-26259

CVE-2021-26259 is a high-severity vulnerability in Htmldoc Project Htmldoc with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 6.8
EPSS exploit prediction: 1% (63rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Htmldoc Project Htmldoc
Published: 2022-03-03
Last modified: 2026-06-17

Description

A flaw was found in htmldoc in v1.9.12. Heap buffer overflow in render_table_row(),in ps-pdf.cxx may lead to arbitrary code execution and denial of service.

Frequently asked questions

What is CVE-2021-26259?: A flaw was found in htmldoc in v1.9.12. Heap buffer overflow in render_table_row(),in ps-pdf.cxx may lead to arbitrary code execution and denial of service.
How severe is CVE-2021-26259?: CVE-2021-26259 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-26259 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (63rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-26259?: CVE-2021-26259 affects Htmldoc Project Htmldoc. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-26259?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-26259 published?: CVE-2021-26259 was published on 2022-03-03 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:htmldoc_project:htmldoc:1.9.12:*:*:*:*:*:*:*

More vulnerabilities in Htmldoc Project Htmldoc

CVE-2024-46478 — Critical (CVSS 9.8): HTMLDOC v1.9.18 contains a buffer overflow in parse_pre function,ps-pdf.cxx:5681.
CVE-2024-45508 — Critical (CVSS 9.8): HTMLDOC before 1.9.19 has an out-of-bounds write in parse_paragraph in ps-pdf.cxx because of an attempt to strip…
CVE-2021-23165 — Critical (CVSS 9.8): A flaw was found in htmldoc before v1.9.12. Heap buffer overflow in pspdf_prepare_outpages(), in ps-pdf.cxx may lead to…
CVE-2021-23158 — Critical (CVSS 9.8): A flaw was found in htmldoc in v1.9.12. Double-free in function pspdf_export(),in ps-pdf.cxx may result in a…
CVE-2021-20308 — Critical (CVSS 9.8): Integer overflow in the htmldoc 1.9.11 and before may allow attackers to execute arbitrary code and cause a denial of…
CVE-2021-34121 — High (CVSS 7.8): An Out of Bounds flaw was discovered in htmodoc 1.9.12 in function parse_tree() in toc.cxx, this possibly leads to…

All CVEs affecting Htmldoc Project Htmldoc →

Other CWE-787 (Out-of-bounds Write) vulnerabilities

CVE-2026-42369 — Critical (CVSS 10.0): GV-VMS V20 is a Video Monitoring Software used to gather the feeds of many surveillance cameras and manage other…
CVE-2026-4746 — Critical (CVSS 10.0): Out-of-bounds Write vulnerability in timeplus-io proton (base/poco/Foundation/src‎ modules). This vulnerability is…
CVE-2025-43300 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 15.8.5 and iPadOS…
CVE-2025-24201 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved checks to prevent unauthorized actions. This issue is fixed in…
CVE-2024-42479 — Critical (CVSS 10.0): llama.cpp provides LLM inference in C/C++. The unsafe `data` pointer member in the `rpc_tensor` structure can cause…
CVE-2024-39791 — Critical (CVSS 10.0): Stack-based buffer overflow vulnerabilities affecting Vonets industrial wifi bridge relays and wifi bridge…

Browse all CWE-787 (Out-of-bounds Write) vulnerabilities →