Authentication Bypass in Forem (CVE-2026-48780)
Summary
Authentication bypass in Forem (CVE-2026-48780). Confidential information can be exposed externally. Exploitable via a2ab6d4.
Original description
The description as published by the source.
Forem is open source software for building communities. Prior to commit a2ab6d4, a maliciously crafted email address could allow an attacker to bypass domain allowlist or denylist restrictions and gain access to invite-only forem deployments. The issue is patched as of a2ab6d4. As a workaround, some SMTP servers and email delivery providers may drop or refuse to send maliciously crafted email addresses.
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-2026-48780 has been found in Forem.
Attackers can target a specific entry point like a2ab6d4 over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 8.2/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Forem CVE-2026-48780" on the vendor's site.
CVE-2026-48780 (Forem) — CWE-287 / CVSS v3 8.2
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: a2ab6d4
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.
Authentication bypass (CWE-287) exists in Forem. Attackers reach the vulnerable code path via a2ab6d4 without authentication.
Check the vendor advisory for the affected versions of Forem. Attack surface: a2ab6d4.
Severity: High (CVSS 8.2/10). Confidential information can be exposed externally.
Update to the patched release per vendor advisory.
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 'Forem' . 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 'Forem' . | 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
Foremを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-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。
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- patch github.com