CVE-2026-33167
Rails has a possible XSS vulnerability in its Action Pack debug exceptions
Description
### Impact The debug exceptions page does not properly escape exception messages. A carefully crafted exception message could inject arbitrary HTML and JavaScript into the page, leading to XSS. This affects applications with detailed exception pages enabled (`config.consider_all_requests_local = true`), which is the default in development. ### Releases The fixed releases are available at the normal locations. ### Credit This issue was responsibly reported by Hackerone researcher [fbettag](https://hackerone.com/fbettag).
How to fix CVE-2026-33167
To remediate CVE-2026-33167, upgrade the affected package to a fixed version below.
- —upgrade to 8.1.2.1 or later
Is CVE-2026-33167 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 8.1.0, < 8.1.2.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U |