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PatchSiren cyber security CVE debrief

CVE-2026-55659 gristlabs CVE debrief

CVE-2026-55659 is a high-severity cross-site scripting vulnerability in Grist spreadsheet software prior to version 1.7.15. The vulnerability allows an attacker to inject malicious scripts into the application, potentially leading to escalation of privileges. The vulnerability exists due to improper escaping of user-controlled values in server-rendered Grist pages and inline scripts. An attacker could inject malicious scripts, which would run in the victim's Grist origin and allow for unauthorized access to sensitive data. Users of Grist spreadsheet software, particularly those with sensitive data, should be aware of this vulnerability and take steps to mitigate it.

Vendor
gristlabs
Product
grist-core
CVSS
HIGH 7.7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-10
Original CVE updated
2026-07-10
Advisory published
2026-07-10
Advisory updated
2026-07-10

Who should care

Users of Grist spreadsheet software, particularly those with sensitive data, should be aware of this vulnerability and take steps to mitigate it. Affected operators should review the official advisory for more information and implement additional security measures, such as input validation and output encoding. Vulnerability management and security teams should monitor for suspicious activity and implement incident response plans.

Technical summary

The vulnerability exists due to improper escaping of user-controlled values in server-rendered Grist pages and inline scripts. An attacker could inject malicious scripts, which would run in the victim's Grist origin and allow for unauthorized access to sensitive data. The vulnerability allows an attacker to inject malicious scripts into the application, potentially leading to escalation of privileges. Grist spreadsheet software uses Python as its formula language and is vulnerable to cross-site scripting.

Defensive priority

High

Recommended defensive actions

  • Upgrade to Grist version 1.7.15 or later
  • Implement additional security measures, such as input validation and output encoding
  • Monitor for suspicious activity and implement incident response plans
  • 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
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record was published on 2026-07-10T21:16:56.577Z and has not been modified since then. The NVD entry is currently 7.7 HIGH. There is limited information available about the vulnerability, and defenders should verify the affected scope and severity with the vendor. The Grist spreadsheet software uses Python as its formula language and is vulnerable to cross-site scripting. Users should review the official advisory for more information.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-10T21:16:56.577Z and has not been modified since then.