JPEG XL (aka jpeg-xl) through 0.3.2 allows writable memory corruption.
Conclusion & alert: CVE-2021-27804 is rated High Risk (65.2/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 0.82%). Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.
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 | 2025-11-21 | 0.63% | 0.82% | +0.19% |
| 2 | 2025-11-18 | 0.82% | 0.63% | -0.19% |
| 3 | 2025-03-30 | — | 0.82% | — |
Full EPSS history (11 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.8 | 3.1 | CRITICAL |
|
3.9 | 5.9 | [email protected] |
| 7.5 | 2.0 | HIGH |
|
10.0 | 6.4 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
unimportant | CVE-2021-27804 unimportant priority: Debian including 1 source packages (jpeg-xl), 4 status rows across 4 suites (bookworm, forky, sid, trixie): resolved 4. | https://security-tracker.debian.org/tracker/CVE-2021-27804 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| libjxl_project | libjxl | <= 0.3.2 | cpe:2.3:a:libjxl_project:libjxl:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| http://packetstormsecurity.com/files/161623/jpeg-xl-0.3.1-Memory-Corruption.html | Third Party Advisory |
| http://seclists.org/fulldisclosure/2021/Mar/2 | Third Party Advisory |
| http://www.openwall.com/lists/oss-security/2021/03/01/3 | Mailing List Third Party Advisory |
| https://gitlab.com/wg1/jpeg-xl/-/tags | Third Party Advisory |