# CVE-2026-12888: HTML injection in the Canarytoken Google Chat notification

> Attackers can inject HTML into Google Chat notifications, enabling interface manipulation and potential phishing via inserted links.

- **Severity:** Low 2.0 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N/E:P/AU:N/RE:L/U:Green`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 22 Jun 2026
- **Updated:** 22 Jun 2026
- **Also known as:** GHSA-vcfc-7466-8q65

## What is CVE-2026-12888?

CVE-2026-12888 is a low-severity cross-site scripting vulnerability in Thinkst Applied Research Canarytokens, published on 22 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

An HTML injection vulnerability exists in the Google Chat webhook notification  sent by Thinkst Applied Research Canarytokens, enabling Interface Manipulation in Google Chat. An attacker can insert limited HTML content including links.

This issue affects Canarytokens: from Docker tag sha-4aef1db90 before sha-8ab4dccd, from Git commit 4aef1db90 before 8ab4dccd.

Weakness: CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2026-12888?


## How do I fix CVE-2026-12888?

No fix has been published for CVE-2026-12888 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-12888 being exploited?

There is no known exploitation of CVE-2026-12888 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-12888 and fix it if it is affected.

What it is: CVE-2026-12888 is a low-severity cross-site scripting vulnerability in Thinkst Applied Research Canarytokens, published on 22 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-12888 in the wild and no public exploit code.

Affected product: Thinkst Applied Research Canarytokens. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-12888/ (Markdown: https://insights.sbomify.com/CVE-2026-12888/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-12888
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-12888
- OSV: https://osv.dev/vulnerability/CVE-2026-12888

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-12888/
Summaries are generated and may contain mistakes; the official description above is the record.