The all-in-one-seo-pack plugin before 3.2.7 for WordPress (aka All in One SEO Pack) is susceptible to Stored XSS due to improper encoding of the SEO-specific description for posts provided by the plugin via unsafe placeholder replacement.
Conclusion & alert: CVE-2019-16520 is rated High Exploit Risk (63.5/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.14%). Core evidence: 2 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
| EDB-ID | Source | Kind | Published | Link |
|---|---|---|---|---|
| — | nvd_ref | exploit_tag | Exploit-DB ↗ | |
| — | nvd_ref | exploit_tag | Exploit-DB ↗ |
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 | 2026-03-04 | 1.56% | 1.14% | -0.42% |
| 2 | 2026-03-01 | 1.14% | 1.56% | +0.42% |
| 3 | 2026-02-04 | — | 1.14% | — |
Full EPSS history (48 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.4 | 3.1 | MEDIUM |
|
2.3 | 2.7 | [email protected] |
| 3.5 | 2.0 | LOW |
|
6.8 | 2.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| semperplugins | all_in_one_seo_pack | < 3.2.7 | cpe:2.3:a:semperplugins:all_in_one_seo_pack:*:*:*:*:*:wordpress:*:* |
| URL | Tags |
|---|---|
| http://www.openwall.com/lists/oss-security/2019/10/16/5 | Exploit Mailing List Third Party Advisory |
| https://github.com/sbaresearch/advisories/tree/public/2019/SBA-ADV-20190913-04_WordPress_Plugin_All_in_One_SEO_Pack | Exploit Third Party Advisory |
| https://github.com/semperfiwebdesign/all-in-one-seo-pack/issues/2888 | Patch Third Party Advisory |
| https://semperplugins.com/all-in-one-seo-pack-changelog/ | Release Notes Vendor Advisory |
| https://wordpress.org/plugins/all-in-one-seo-pack/#developers | Product Third Party Advisory |
| https://wpvulndb.com/vulnerabilities/9915 | Third Party Advisory |