CVE-2026-28355: thinkst canarytokens · Cross-site Scripting
Affects thinkst canarytokensSource CVE Database V5
Not known to be exploited · CVSS 1.3 Low.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 35% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:UExploitation evidence
Disclosed: evidence found.
CVE published 27 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| thinkstcanarytokens | Affected
| Fixed in– |
AI-suggested
To mitigate CVE-2026-28355, organizations should immediately update their Canarytokens installations to the latest version, specifically pulling Docker images at or after commit sha-7ff0e12 where the vulnerability is patched. For users of the official Canarytokens.org service, no action is required as the patch is already applied. Additionally, administrators should educate users about the risks of clicking untrusted Canarytoken installation links, especially those received from unknown or suspicious sources. Implementing Content Security Policy (CSP) headers on the Canarytokens web interface can further reduce the risk of script injection exploitation. Regular code reviews and input validation enhancements should be enforced to prevent similar injection flaws. Monitoring logs for unusual Canarytoken installation link accesses or unexpected script execution behaviors can help detect attempted exploitation. Finally, security teams should maintain awareness of updates from thinkst and apply patches promptly to minimize exposure.
Description
Canarytokens help track activity and actions on a network. Versions prior to `sha-7ff0e12` have a Self Cross-Site Scripting vulnerability in the "PWA" Canarytoken, whereby the Canarytoken's creator can attack themselves or someone they share the link with. The creator of a PWA Canarytoken can insert Javascript into the title field of their PWA token. When the creator later browses the installation page for their own Canarytoken, the Javascript executes. This is a self-XSS. An attacker could create a Canarytoken with this self-XSS, and send the install link to a victim. When they click on it, the Javascript would execute. However, no sensitive information (ex.session information) will be disclosed to the malicious actor. This issue is now patched on Canarytokens.org. Users of self-hosted Canarytokens installations can update by pulling the latest Docker image, or any Docker image after sha-7ff0e12.