Vulnerability in morgan (CVE-2026-5078)
Summary
Vulnerability in morgan (CVE-2026-5078). Risk of unauthorized operations or information disclosure. Exploitable via Authorization. Mitigation: upgrade to 1.11.0 or later.
Original description
The description as published by the source.
Impact: The morgan logging middleware's :remote-user token extracts the Basic auth username from the Authorization request header and writes it to the log stream without neutralizing control characters. An unauthenticated attacker can send a crafted Authorization Basic header containing CR or LF bytes to inject forged log lines, breaking the one-request-per-line structure of access logs and enabling log forgery against downstream log consumers. The built-in combined, common, default, and short formats are affected, as well as any custom format that references :remote-user. Affected versions: morgan 1.2.0 through 1.10.1. Patches: upgrade to morgan 1.11.0, which neutralizes control characters in the :remote-user token output. Workarounds: use a custom format string that does not include :remote-user.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-5078 has been found in morgan.
Attackers can target a specific entry point like Authorization over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: upgrade morgan to 1.11.0 or later.
If unsure, ask your IT team or search "morgan CVE-2026-5078" on the vendor's site.
CVE-2026-5078 (morgan) — CWE-117 / CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: Authorization / combined / common / default
Patched: 1.11.0 — apply immediately
Workaround: Use a custom format string that does not include :remote-user.
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.
A vulnerability (CWE-117) exists in morgan. Attackers reach the vulnerable code path via Authorization without authentication.
Check the vendor advisory for the affected versions of morgan. Attack surface: Authorization / combined / common / default.
Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure.
Update to 1.11.0.
Workaround: Use a custom format string that does not include :remote-user.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'morgan' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'morgan' . | 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
morganを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
Use a custom format string that does not include `:remote-user`.パッチが適用されるまでの応急処置として、Use a custom format string that does not include
:remote-user. を実施。回避策の副作用 (機能低下) を確認した上で。 -
3Apply patch patch
Upgrade morgan to 1.11.0ステージング環境で 1.11.0 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を含めること。
-
4Post-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。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-5078 node-morgan
- Ubuntu UBUNTU-CVE-2026-5078 node-morgan
References
- advisory cna.openjsf.org
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- web github.com