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PatchSiren cyber security CVE debrief

CVE-2026-20216 Cisco CVE debrief

CVE-2026-20216 is a vulnerability in the InstallShield file format parser of ClamAV, which could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device. This vulnerability is due to improper handling of temporary resources during file scanning. The vulnerability affects ClamAV and Cisco Secure Endpoint. Users of these products should be aware of this vulnerability and take necessary precautions to prevent exploitation.

Vendor
Cisco
Product
Secure Endpoint
CVSS
HIGH 7.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-01
Original CVE updated
2026-07-09
Advisory published
2026-07-01
Advisory updated
2026-07-09

Who should care

Users of Cisco Secure Endpoint and ClamAV, particularly those responsible for vulnerability management, security teams, and operators of affected platforms, should be aware of this vulnerability and take necessary precautions to prevent exploitation. This includes reviewing official advisories, assessing exposure, and planning for updates or mitigations.

Technical summary

The vulnerability exists in the InstallShield file format parser of ClamAV. An attacker could exploit this vulnerability by submitting a crafted InstallShield file to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to terminate the ClamAV scanning process and temporarily consume available system resources, resulting in a DoS condition on the affected software. This issue is due to improper handling of temporary resources during file scanning.

Defensive priority

High

Recommended defensive actions

  • Update ClamAV to version 1.5.4 or later
  • Update Cisco Secure Endpoint to version 1.29.0 or later for Linux, 8.6.3 or later for Windows, and 1.27.3 or later for macOS
  • Implement network segmentation to limit the spread of the attack
  • Monitor system resources for unusual consumption patterns
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record was published on 2026-07-01T17:16:29.973Z and was last modified on 2026-07-09T18:09:19.380Z. The NVD entry is currently Analyzed. This information is based on the NVD entry and the CVE record. The vulnerability affects ClamAV and Cisco Secure Endpoint. Users should verify their deployments and review official advisories for affected scope and severity.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-20216 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-20216

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-20216 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-20216

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.