CVE-2026-33170Patch(rubyonrails / rails)

LOWCVSS 6.1 · MEDIUM

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Patch rubyonrails rails systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

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.

0.5/ 10 priority

Sources & remediation

Weakness type (CWE)
CWE-79

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

STABLE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • rails

Threat summary

  • Patch or workaround signal is available
  • 5 mentions across 3 observed days
  • Momentum state: stable

What's happening

  • Patch or workaround mentioned in 2 signals
  • Technical details provided in 3 signals
  • Disclosure: 2 classified signals
  • General: 1 classified signal
  • Peaked 1d ago at 3 mentions (2026-03-24); latest day: 1
  • 5 total mentions across 3 days

Affected systems

Products
rails

Deep dive

Activity timeline5 mentions / 3d
01223Mentions · 2026-03-23: 1Mentions · 2026-03-24: 3Mentions · 2026-04-10: 1Patch / Workaround · 2026-03-23: 1Patch / Workaround · 2026-03-24: 1Technical Details · 2026-03-23: 1Technical Details · 2026-03-24: 1Technical Details · 2026-04-10: 103-2303-2404-10
Signal classification3 categories
Patch
240.0%
Disclosure
240.0%
General
120.0%
Referenced assets3 URLs
Classification over time
DateTotalLabels
2026-03-231
Patch1
2026-03-243
Disclosure1General1Patch1
2026-04-101
Disclosure1
Full discourse5 posts
  • Vito Botta@vitobotta
    Disclosure

    CVE-2026-33170 is fascinating because it breaks Rails' own XSS protection system. SafeBuffer#% operator fails to propagate the html_unsafe flag when creating new buffers, so content that should be escaped gets marked as safe. It's a flaw in the security mechanism itself, not just another injection point. Rails apps using SafeBuffer with the % operator for formatting could be exposing XSS vulnerabilities without realising their protection layer is compromised.

    Post summary

    CVE-2026-33170 reveals that Rails' SafeBuffer#% operator incorrectly propagates the html_unsafe flag, letting malicious content escape XSS protection and exposing applications to cross‑site scripting attacks.

    0001099
    922 followersView on X
  • CVEarity@CVEarity
    General

    ⚡ New CVE Alert: CVE-2026-33170 📊 Severity: 5.3 🚨 Risk Level: Medium 🧩 Affects: Multiple / Unspecified Products Reference: https://nvd.nist.gov/vuln/detail/CVE-2026-33170 #CVE-2026-33170 #CVE #Medium #CyberSecurity #InfoSec https://t.co/bVSjgHYXNT

    Post summary

    This tweet announces CVE-2026-33170 with a medium CVSS score but offers no technical or operational details beyond the NVD reference.

    0000023
    111 followersView on X
  • Infoflowcloud@infoflowcloud
    Disclosure

    🚨*CVE* CVE-2026-33170 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, `SafeBu… https://www.cve.org/CVERecord?id=CVE-2026-33170 ----- Traducción: CVE-2026-33170 Act… http://infoflow.cloud`

    Post summary

    The post announces CVE‑2026‑33170, highlighting affected ActiveSupport versions without providing a PoC, exploit, or patch information.

    0000041
    60 followersView on X
  • CVE@CVEnew
    Patch

    CVE-2026-33170 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, `SafeBu… https://www.cve.org/CVERecord?id=CVE-2026-33170

    Post summary

    The CVE-2026-33170 affects Active Support in older Rails versions, and patches are available in releases 8.1.2.1, 8.0.4.1, and 7.2.3.1.

    00000194
    56.8K followersView on X
  • ダース葱@darthnegi
    Patch

    🚀 Ruby on Rails v7.2.3.1 がリリースされました。 📦 種別: patch ✨ 主な変更点: • Active Support: NumberConverterにおける指数表記を拒否するよう修正(CVE-2026-33176) • Active Support: `SafeBuffer#%` がunsafeステータスを保持するように修正(CVE-2026-33170) • Active Support: NumberToDelimitedConverterのパフォーマンスを改善(CVE-2026-33169) • Action View: タグヘルパーで空の属性名をスキップし、不正なHTML生成を回避(CVE-2026-33168) • Active Storage: DirectUploadControllerでユーザー提供のメタデータをフィルタリング(CVE-2026-33173) • Active Storage: 最大ストリーミングチャンクサイズを設定可能に(CVE-2026-33174) • Active Storage: 範囲リクエストを単一の範囲に制限(CVE-2026-33658) • Active Storage: `DiskService`におけるパストラバーサルを防止(CVE-2026-33195) • Active Storage: `DiskService#delete_prefixed`におけるグロブインジェクションを防止(CVE-2026-33202) ⚠️ 破壊的変更: • `DiskService#delete_prefixed`の変更により、既存のグロブメタ文字展開に依存するコードは動作しなくなります。 🔧 重要な修正: • Active Support: NumberConverterにおける指数表記を拒否するよう修正(CVE-2026-33176) • Active Support: `SafeBuffer#%` がunsafeステータスを保持するように修正(CVE-2026-33170) • Active Support: NumberToDelimitedConverterのパフォーマンスを改善(CVE-2026-33169) • Action View: タグヘルパーで空の属性名をスキップし、不正なHTML生成を回避(CVE-2026-33168) • Active Storage: DirectUploadControllerでユーザー提供のメタデータをフィルタリング(CVE-2026-33173) • Active Storage: 最大ストリーミングチャンクサイズを設定可能に(CVE-2026-33174) • Active Storage: 範囲リクエストを単一の範囲に制限(CVE-2026-33658) • Active Storage: `DiskService`におけるパストラバーサルを防止(CVE-2026-33195) • Active Storage: `DiskService#delete_prefixed`におけるグロブインジェクションを防止(CVE-2026-33202) #GitHub #Release #Ruby on Rails

    Post summary

    Ruby on Rails v7.2.3.1 release includes critical patches for several CVEs, addressing path traversal, glob injection, and unsafe HTML generation vulnerabilities.

    0000036
    2 followersView on X
CPE platform detail1 entries

1 of 1 entries

PartVendorProductVersionTarget SWTarget HW
Apprubyonrailsrails---

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