Vulnerability in drupal/flag_attendance_field (CVE-2026-55809)
Summary
Vulnerability in drupal/flag_attendance_field (CVE-2026-55809). Confidential information can be exposed externally. Exploitable via flag_attendance_field. Mitigation: upgrade to 1.2.0 or later.
Original description
The description as published by the source.
The Flag attendance field module gives you the ability to add attendance by depending on Flag module.
flag_attendance_field stores some data as PHP-serialized strings. In some situations, malicious data can be written directly to the field. This can lead to an object injection vulnerability when the data are unserialized.
This vulnerability is mitigated by the fact that an attacker must have permission to edit a content entity with an attached flag_attendance_field field. In addition, the core JSON:API module must be enabled with the option "Accept all JSON:API create, read, update, and delete operations", which is not the default, or the attacker needs some other way to edit field values directly.
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-2026-55809 has been found in drupal/flag_attendance_field.
Attackers can target a specific entry point like flag_attendance_field over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 8.1/10.
What to do: upgrade drupal/flag_attendance_field to 1.2.0 or later.
If unsure, ask your IT team or search "drupal/flag_attendance_field CVE-2026-55809" on the vendor's site.
CVE-2026-55809 (drupal/flag_attendance_field) — CWE-915 / CVSS v3 8.1
Attack vector: remote (network-reachable) / no user interaction
Attack surface: flag_attendance_field
Patched: 1.2.0 — 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.
A vulnerability (CWE-915) exists in drupal/flag_attendance_field. Attackers reach the vulnerable code path via flag_attendance_field.
Check the vendor advisory for the affected versions of drupal/flag_attendance_field. Attack surface: flag_attendance_field.
Severity: High (CVSS 8.1/10). Confidential information can be exposed externally.
Update to 1.2.0.
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 'drupal/flag_attendance_field' . 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 'drupal/flag_attendance_field' . | 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
drupal/flag_attendance_field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 drupal/flag_attendance_field to 1.2.0ステージング環境で 1.2.0 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。
-
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
- web drupal.org
- web nvd.nist.gov
- web github.com