Cross-Site Scripting (XSS) in getgrav/grav (CVE-2026-55890)
Summary
Cross-site scripting in getgrav/grav (CVE-2026-55890). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 2.0.0-rc.9 or later.
Original description
The description as published by the source.
Grav is a file-based Web platform. Prior to 2.0.0-rc.9, Grav's incomplete fix for stored XSS through the Markdown media attribute action (CVE-2026-42841) leaves the sibling MediaObjectTrait::style method reachable through the same Markdown excerpt-action pipeline, allowing an editor to save Markdown image style parameters that are written into the rendered img style attribute without sanitization. This issue is fixed in version 2.0.0-rc.9.
Source: GitHub Security Advisories (Global) 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-2026-55890 has been found in getgrav/grav.
Risk of unauthorized operations or information disclosure. CVSS score: 4.8/10.
What to do: upgrade getgrav/grav to 2.0.0-rc.9 or later.
If unsure, ask your IT team or search "getgrav/grav CVE-2026-55890" on the vendor's site.
CVE-2026-55890 (getgrav/grav) — CWE-79 / CVSS v3 4.8
Attack vector: remote (network-reachable)
Patched: 2.0.0-rc.9 — 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.
Cross-site scripting (XSS) (CWE-79) exists in getgrav/grav.
Check the vendor advisory for the affected versions of getgrav/grav.
Severity: Medium (CVSS 4.8/10). Risk of unauthorized operations or information disclosure.
Update to 2.0.0-rc.9.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'getgrav/grav' . 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
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1Identify exposure identify
grep -r 'getgrav/grav' . | 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
getgrav/gravを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade getgrav/grav to 2.0.0-rc.9ステージング環境で 2.0.0-rc.9 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。
-
3Post-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
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- patch github.com
- web github.com
- web github.com
- web github.com