← Back
CVE-2026-54905
medium
CVSS 5.5
Vulnerability in concurrent-ruby (CVE-2026-54905)
Summary
vulnerability in concurrent-ruby (CVE-2026-54905). Confidential information can be exposed externally. Exploitable via ``WRITE_LOCK_HELD``. Mitigation: upgrade to `1.3.7` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-54905** has been found in concurrent-ruby.
Attackers can target a specific entry point like ``WRITE_LOCK_HELD`` over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 5.5/10.
What to do: upgrade concurrent-ruby to **1.3.7** or later.
If unsure, ask your IT team or search "concurrent-ruby CVE-2026-54905" on the vendor's site.
CVE-2026-54905 (concurrent-ruby) — CWE-128 / CVSS v3 5.5
Attack vector: local / no user interaction
Attack surface: `WRITE_LOCK_HELD` / `try_write_lock` / `true` / `RUNNING_WRITER`
Patched: `1.3.7` — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
❓ What is the problem
**A vulnerability** (CWE-128) exists in concurrent-ruby. Attackers reach the vulnerable code path via ``WRITE_LOCK_HELD`` without authentication.
📍 Affected scope
concurrent-ruby — . Attack surface: `WRITE_LOCK_HELD` / `try_write_lock` / `true` / `RUNNING_WRITER`.
🔥 Severity
Severity: Medium (CVSS 5.5/10). Confidential information can be exposed externally
🔧 How to fix
Update to **1.3.7**.
🛡️ Workaround
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
🔍 Detection
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run `grep -r 'concurrent-ruby' .` against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response Actions (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'concurrent-ruby' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で `concurrent-ruby` を grep し、稼働しているサービス・バージョンを把握する。
-
6Apply patch patch
Upgrade concurrent-ruby to 1.3.7ステージング環境で 1.3.7 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 3 で見つけた異常検知の続報チェックを含めること。
-
7Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 3 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
rubygems
concurrent-ruby
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.3.7"}]}]