PatchSiren cyber security CVE debrief
CVE-2010-0249 Microsoft CVE debrief
CVE-2010-0249 is listed by CISA in the Known Exploited Vulnerabilities catalog as a Microsoft Internet Explorer use-after-free vulnerability. In practical terms, CISA treats it as a vulnerability requiring urgent defensive action. The supplied source guidance is to apply vendor mitigations, follow BOD 22-01 guidance where applicable for cloud services, or discontinue use of the product if mitigations are unavailable.
- Vendor
- Microsoft
- Product
- Internet Explorer
- CVSS
- HIGH 8.8
- CISA KEV
- Listed
- Original CVE published
- 2026-05-20
- Original CVE updated
- 2026-05-20
- Advisory published
- 2026-05-20
- Advisory updated
- 2026-05-20
Who should care
Security and endpoint teams, vulnerability management owners, and administrators responsible for environments where Internet Explorer is still present or accessible.
Technical summary
The supplied corpus identifies the issue as a use-after-free vulnerability in Microsoft Internet Explorer and places it in CISA’s Known Exploited Vulnerabilities catalog. Beyond that, the source set does not provide version ranges, attack preconditions, or patch specifics. The defensible takeaway is that CISA considers the issue actively exploited enough to require prompt mitigation or removal of exposure.
Defensive priority
High priority. KEV listing status means remediation should be treated as urgent, with attention to the supplied due date of 2026-06-03.
Recommended defensive actions
- Confirm whether Internet Explorer is installed, enabled, or reachable in your environment.
- Apply Microsoft vendor mitigations referenced by the official advisory and related guidance.
- If mitigations are unavailable or insufficient, discontinue use of Internet Explorer where possible.
- Follow applicable BOD 22-01 guidance for cloud services if the affected product is used there.
- Track remediation against the supplied KEV due date of 2026-06-03.
- Validate exposure using asset inventory and endpoint configuration checks.
Evidence notes
This debrief is based only on the supplied KEV metadata and the official record links provided in the corpus. The source item states Microsoft Internet Explorer use-after-free vulnerability, marks it as KEV-listed, and instructs defenders to apply vendor mitigations or discontinue use if mitigations are unavailable. No additional exploitation, version, or patch details were included in the supplied corpus.
Official resources
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CVE-2010-0249 CVE record
CVE.org
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CVE-2010-0249 NVD detail
NVD
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CISA Known Exploited Vulnerabilities catalog
CISA - Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
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Source item URL
cisa_kev
Public KEV-listed vulnerability context based on the supplied dates: CISA date added 2026-05-20 and due date 2026-06-03. This summary uses only the provided corpus and official links.