Microsoft Silverlight Information Disclosure Vulnerability
CVE-2013-3896 is a security vulnerability in Microsoft Silverlight, added to CISA KEV on May 25, 2022. Patch order: fourth of four.
What is CVE-2013-3896?
Microsoft Silverlight does not properly validate pointers during access to Silverlight elements, which allows remote attackers to obtain sensitive information via a crafted Silverlight application.
VulnCheck tracked exploitation 468 days before CISA's KEV listing. VulnCheck's broader catalog of in-the-wild exploitation evidence picked this up before it landed on CISA's formal list. Per-CVE fact about this entry; not a population claim about lead time in general.
Who is affected by CVE-2013-3896?
Affects anyone running Microsoft Silverlight. Microsoft products in a small practice typically sit close to credentials, email, or document workflows — treat the patch as in-scope.
What should I do about CVE-2013-3896?
The impacted product is end-of-life and should be disconnected if still in use.
If you don't have someone in-house to verify the patch deployed across every endpoint — or you're not sure whether you're affected — that's exactly the kind of triage we do. Talk with us.
Insurance readiness
Your insurer will ask if this is patched.
Unpatched entries on CISA's Known Exploited Vulnerabilities list are exactly what cyber-insurance carrier questionnaires probe for, and knowing which controls they check is how you keep a renewal from stalling.
Get the free carrier questionnaire →Severity
CVSS base score: 5.5 — MEDIUM
CISA due date
CISA's listed due date: June 15, 2022.
Federal civilian agencies work under CISA's Binding Operational Directive 26-04, which replaced BOD 22-01 on June 10, 2026. It sets the deadline for each affected system by:
- How exposed that system is to the internet
- Whether the attack can be automated
- How much control it gives an attacker
Its table gives catalogued vulnerabilities 3 or 14 days.
None of this binds a private business, but treat the date as a strong recommendation, especially if you handle regulated data (HIPAA, GLBA, ABA model rules).
EPSS
EPSS score: 68.0% — higher than 99% of all scored CVEs.
EPSS estimates the probability of exploitation activity in the next 30 days. Every entry on this site is already confirmed exploited, so read it as relative urgency among the things you still have open, not as permission to wait.
Other exploited Microsoft Silverlight entries
More CISA KEV entries for Microsoft Silverlight. Same product line, same actively-exploited status.
Source
This entry comes from CISA's Known Exploited Vulnerabilities catalog, public US-Government data we pull daily. The plain-language framing and the what-to-do guidance above are ours. View the original entry on cisa.gov.