Vulnerability · CVE-2026-9495
Versions of the package @koa/router from 14.0.0 and before 15.0.0 are vulnerable to Access Control Bypass due to the middleware being silently dropped from the executi…
Published May 26, 2026 · catalog updated Jul 23, 2026 · the affected product
Last checked Oct 25, 2026. A connected source was read within the last 7 days.
Check if you run it
No confirmed exploitation is on record for CVE-2026-9495. EPSS is 0.36%. 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
- Medium5.5
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.36%
- Remediation
- Advisory link
- Affected products
- See sources for product scope
Versions of the package @koa/router from 14.0.0 and before 15.0.0 are vulnerable to Access Control Bypass due to the middleware being silently dropped from the execution chain when the router prefix contains path parameters. Depending on what the skipped middleware was supposed to protect, an attacker could bypass authentication and authorization, evade rate limiting or bypass input sanitization.
No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.
How to fix CVE-2026-9495
No stored fix
No vendor fix text is stored. Use the linked advisory before you change production.
Version check
No version range is stored, so an installed version cannot be checked on this page.
Advisory
Open the cve_org record and follow its fix.
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-2026-9495. EPSS is 0.36%. 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-284: Improper Access Control. EPSS 0.36%. 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.
May 26, 2026 · NIST NVD
Detected
Versions of the package @koa/router from 14.0.0 and before 15.0.0 are vulnerable to Access Control Bypass due to the middleware being silently dropped from the execution chain when the router prefix contains path parameters. Depending on what the skipped middleware was supposed to protect, an attacker could bypass authentication and authorization, evade rate limiting or bypass input sanitization.
Jul 23, 2026 · NIST NVD
Updated
Versions of the package @koa/router from 14.0.0 and before 15.0.0 are vulnerable to Access Control Bypass due to the middleware being silently dropped from the execution chain when the router prefix contains path parameters. Depending on what the skipped middleware was supposed to protect, an attacker could bypass authentication and authorization, evade rate limiting or bypass input sanitization.
Sources
- CVE.orgVulnerability recordCVE-2026-9495
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-9495
30-day exploitation probability 0.36%
first.org - NIST NVDVulnerability recordCVE-2026-9495
Versions of the package @koa/router from 14.0.0 and before 15.0.0 are vulnerable to Access Control Bypass due to the middleware being silently dropped from the execution chain when the router prefix contains path parameters. Depending on what the skipped middleware was supposed t
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 25, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.
- FIRST EPSSOct 25, 2026
- NIST NVDOct 18, 2026
- CVE.orgOct 16, 2026