In Deark before v1.5.8, a specially crafted input file can cause a division by zero in (src/fmtutil.c) because of the value of pixelsize.
Conclusion & alert: CVE-2021-28856 is rated Low Risk (34.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.17%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2025-03-17 | 0.06% | 0.17% | +0.11% |
| 2 | 2023-03-07 | 0.89% | 0.06% | -0.83% |
| 3 | 2022-04-01 | — | 0.89% | — |
Full EPSS history (6 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.5 | 3.1 | MEDIUM |
|
1.8 | 3.6 | [email protected] |
| 4.3 | 2.0 | MEDIUM |
|
8.6 | 2.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| entropymine | deark | < 1.5.8 | cpe:2.3:a:entropymine:deark:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://fatihhcelik.github.io/posts/Division-By-Zero-Deark/ | Patch Third Party Advisory |
| https://github.com/fuzzing2026/CVE-PoCs/tree/main/deark-CVE-2021-28856 | |
| https://github.com/jsummers/deark/commit/62acb7753b0e3c0d3ab3c15057b0a65222313334 | Patch Third Party Advisory |