Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, SafeBuffer#% does not propagate the @html_unsafe flag to the newly created buffer. If a SafeBuffer is mutated in place (e.g. via gsub!) and then formatted with % using untrusted arguments, the result incorrectly reports html_safe? == true, bypassing ERB auto-escaping and possibly leading to XSS. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.
CVE-2026-33170
This medium-severity CVE scores 6.1 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 74% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.1
- EG Score
- 6.1(medium)
- EG Risk
- 32(Track)EG Risk 32/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity61% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 26%
- KEV
- Not listed
Published
March 24, 2026
Last Modified
June 17, 2026
Advisory Details (7)
Auto-updated Aug 4, 2026Possible XSS vulnerability in SafeBuffer#% in Active Support · Advisory · rails/rails · GitHub
https://github.com/rails/rails/security/advisories/GHSA-89vf-4333-qx8v8.1.2.1
Patch available: rails/rails v8.1.2.1
https://github.com/rails/rails/releases/tag/v8.1.2.18.0.4.1
Patch available: rails/rails v8.0.4.1
https://github.com/rails/rails/releases/tag/v8.0.4.17.2.3.1
Patch available: rails/rails v7.2.3.1
https://github.com/rails/rails/releases/tag/v7.2.3.1commit c1ad0e8e1972 (rails/rails)
Fix landed in rails/rails commit c1ad0e8e1972 — awaiting tagged release
https://github.com/rails/rails/commit/c1ad0e8e1972032f3395853a5e99cea035035bebcommit 6e8a81108001 (rails/rails)
Fix landed in rails/rails commit 6e8a81108001 — awaiting tagged release
https://github.com/rails/rails/commit/6e8a81108001d58043de9e54a06fca58962fc2dbcommit 50d732af3b7c (rails/rails)
Fix landed in rails/rails commit 50d732af3b7c — awaiting tagged release
https://github.com/rails/rails/commit/50d732af3b7c8aaf63cbcca0becbc00279b215b7Affected Packages
(5 across 5 ecosystems)
Debian:11(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| rails | 2:6.0.3.7+dfsg-2 ... 2:7.2.3.2+dfsg-2 (72 versions) | — | — |
Debian:12(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| rails | 2:6.1.7.10+dfsg-1~deb12u1 ... 2:7.2.3.2+dfsg-2 (38 versions) | — | — |
Debian:13(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| rails | 2:7.2.2.1+dfsg-7 ... 2:7.2.3.2+dfsg-2 (10 versions) | — | — |
Debian:14(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| rails | 2:7.2.2.1+dfsg-7 ... 2:7.2.3+dfsg-3 (7 versions) | 2:7.2.3.1+dfsg-1 | — |
RubyGems(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| activesupport | 1.0.0 ... 7.2.3 (482 versions) | 7.2.3.1 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 31× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-09-18 19:28 UTCEPSS rescore
- 2026-09-18 19:28 UTCEPSS rescore
- 2026-09-17 19:30 UTCEPSS rescore
- 2026-09-16 14:08 UTCEPSS rescore
- 2026-09-16 05:15 UTCEPSS rescore
- 2026-09-15 03:11 UTCEPSS rescore
- 2026-09-13 16:47 UTCEPSS rescore
- 2026-09-12 15:01 UTCEPSS rescore
- 2026-09-11 14:52 UTCEPSS rescore
- 2026-09-10 09:34 UTCEPSS rescore
- 2026-09-08 22:00 UTCEPSS rescore
- 2026-09-07 16:01 UTCEPSS rescore
- 2026-09-06 13:47 UTCEPSS rescore
- 2026-09-06 13:47 UTCEPSS rescore
- 2026-09-04 05:06 UTCEPSS rescore
- 2026-09-02 16:08 UTCOSV refresh
- 2026-09-02 14:11 UTCEPSS rescore
- 2026-09-01 13:53 UTCEPSS rescore
- 2026-09-01 04:39 UTCEPSS rescore
- 2026-09-01 04:39 UTCEPSS rescore
- 2026-08-30 19:17 UTCEPSS rescore
- 2026-08-30 01:22 UTCEPSS rescore
- 2026-08-28 21:41 UTCEPSS rescore
- 2026-08-27 14:25 UTCEPSS rescore
- 2026-08-26 14:46 UTCEPSS rescore
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- 2026-08-25 13:49 UTCEPSS rescore
- 2026-08-24 14:17 UTCEPSS rescore
- 2026-08-23 00:19 UTCEPSS rescore
- 2026-08-21 23:49 UTCEPSS rescore
- 2026-08-20 22:55 UTCEPSS rescore
- 2026-08-20 22:55 UTCEPSS rescore
- 2026-08-19 17:03 UTCEPSS rescore
- 2026-08-18 13:48 UTCEPSS rescore
- 2026-08-17 13:47 UTCEPSS rescore
- 2026-08-16 14:56 UTCEPSS rescore
- 2026-08-16 10:43 UTCEG score recompute
- 2026-08-16 02:14 UTCEPSS rescore
- 2026-08-15 01:30 UTCEPSS rescore
- 2026-08-14 06:55 UTCEG score recompute
- 2026-08-13 22:00 UTCEPSS rescore
- 2026-08-12 22:45 UTCEG score recompute
- 2026-08-12 13:50 UTCEPSS rescore
- 2026-08-11 21:12 UTCEG score recompute
- 2026-08-11 00:00 UTCEPSS rescore
- 2026-08-10 08:05 UTCEG score recompute
- 2026-08-09 13:46 UTCEPSS rescore
- 2026-08-09 06:31 UTCEG score recompute
- 2026-08-08 16:37 UTCEPSS rescore
- 2026-08-07 16:53 UTCEG score recompute
- 2026-08-06 13:46 UTCEPSS rescore
- 2026-08-06 01:15 UTCEG score recompute
- 2026-08-05 19:17 UTCEPSS rescore
- 2026-08-04 15:10 UTCEPSS rescore
- 2026-08-04 10:38 UTCEPSS rescore
- 2026-08-03 23:59 UTCEG score recompute
- 2026-08-03 10:36 UTCEPSS rescore
- 2026-08-02 15:52 UTCEG score recompute
- 2026-08-02 02:27 UTCEPSS rescore
- 2026-08-01 04:16 UTCEPSS rescore
- 2026-07-30 16:28 UTCEPSS rescore
- 2026-07-30 01:30 UTCEPSS rescore
- 2026-07-27 14:31 UTCEG score recompute
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-33170?
When was CVE-2026-33170 disclosed?
Is CVE-2026-33170 actively exploited?
What is the CVSS score of CVE-2026-33170?
How do I remediate CVE-2026-33170?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-33170
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