CVSS 3.1
5.3 mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LCVE-2026-128068 rails-html-sanitizer: Possible regular expression denial of service with certain configurations
Medium (5.3) in rails rails-html-sanitizer. Fixed in rails-html-sanitizer 1.7.2.
On this page
rails-html-sanitizer is responsible for sanitizing HTML fragments in Rails applications. From 1.0.3 through 1.7.1, Rails::HTML::PermitScrubber checks SVG href and xlink:href local references with a pattern whose line-start anchor and whitespace class cause an all-whitespace value to be rescanned from each line start. An attacker who supplies HTML can cause quadratic CPU consumption when an application customizes its allowed tags to include an SVG reference element such as use and permits href or xlink:href. The default allowed tag configuration is not affected. CRuby 3.2 and later uses linear-time regular expression matching for this pattern, while CRuby 3.1 and earlier and JRuby are affected. This issue is fixed in version 1.7.2.
Severity
- Published
- Assigned by
- GitHub_M (CNA)
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
Ask an AI about this CVE
Show the prompt
Explain CVE-2026-128068 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-128068?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-128068?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-128068 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
Badge for a README or a site
An image that stays current: it is drawn from the data each time it is fetched (a host that proxies images, as GitHub does, may show its copy for a while). Markdown:
[](https://cve.bz/cve/CVE-2026-128068)
HTML:
<a href="https://cve.bz/cve/CVE-2026-128068"><img src="https://cve.bz/cve/badge/CVE-2026-128068.svg" alt="CVE-2026-128068"></a>
Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| rails-html-sanitizer | >= 1.0.3, < 1.7.2 |
Fix and patched versions
rails-html-sanitizer(RubyGems): fixed in 1.7.2
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-cpgf-5mjf-73p7 | RubyGems | rails-html-sanitizer | >=1.0.3 <1.7.2 | 1.7.2 |
Attack patterns (CAPEC)
- CAPEC-492 Regular Expression Exponential Blowup
- CAPEC-147 XML Ping of the Death Likelihood: Low · Severity: Medium
- CAPEC-227 Sustained Client Engagement
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.