Vulnerability · CVE-2026-40451
DeepL Chrome browser extension versions from v1.22.0 to v.1.23.0 contain a cross-site scripting vulnerability, which allows an attacker to execute arbitrary script in…
Published Apr 22, 2026 · catalog updated Jun 17, 2026 · the affected product
Check if you run it
No confirmed exploitation is on record for CVE-2026-40451. EPSS is 0.26%. Act only if a listed version of the affected product is installed.
Gaps on this record
- No plain product name is stored. The page cannot tell you which product to check.
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- Medium5.1
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.26%
- Remediation
- Advisory link
- Affected products
- See sources for product scope
DeepL Chrome browser extension versions from v1.22.0 to v.1.23.0 contain a cross-site scripting vulnerability, which allows an attacker to execute arbitrary script in a user's browser, and inject malicious HTML into web pages viewed by the user.
No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.
How to fix CVE-2026-40451
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-40451. EPSS is 0.26%. Act only if a listed version of the affected product is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-79: Cross-site Scripting (XSS). EPSS 0.26%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Apr 22, 2026 · NIST NVD
Detected
DeepL Chrome browser extension versions from v1.22.0 to v.1.23.0 contain a cross-site scripting vulnerability, which allows an attacker to execute arbitrary script in a user's browser, and inject malicious HTML into web pages viewed by the user.
Jun 17, 2026 · NIST NVD
Updated
DeepL Chrome browser extension versions from v1.22.0 to v.1.23.0 contain a cross-site scripting vulnerability, which allows an attacker to execute arbitrary script in a user's browser, and inject malicious HTML into web pages viewed by the user.
Sources
- CVE.orgVulnerability recordCVE-2026-40451
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-40451
30-day exploitation probability 0.3%
first.org - NIST NVDVulnerability recordCVE-2026-40451
DeepL Chrome browser extension versions from v1.22.0 to v.1.23.0 contain a cross-site scripting vulnerability, which allows an attacker to execute arbitrary script in a user's browser, and inject malicious HTML into web pages viewed by the user.
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.