CVE-2026-42331General

LOWCVSS 7.7 · HIGH

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Patch affected systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

FOSSBilling is a free, open-source billing and client management system. Prior to version 0.8.0, the Guest API invoice/update endpoint is missing an authorization check present in other invoice-related endpoints, allowing an unauthenticated user with knowledge of an invoice hash to modify the payment gateway associated with an unpaid invoice. An attacker who obtains an invoice hash, which may leak through shared URLs, referrer headers, or email links, can change the `gateway_id` on an unpaid invoice to any payment gateway configured in the system. This does not allow redirecting payments to an arbitrary external endpoint, as the gateway must already be installed and configured by an administrator. The practical impact is further limited by the `invoice_accessible_from_hash` system setting. Version 0.8.0 contains a patch. No known workarounds are available.

0.5/ 10 priority

Sources & remediation

Weakness type (CWE)
CWE-306CWE-863

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

STABLE

Threat summary

  • Patch or workaround signal is available
  • 4 mentions across 4 observed days
  • Momentum state: stable

What's happening

  • Patch or workaround mentioned in 1 signal
  • General: 3 classified signals
  • Disclosure: 1 classified signal
  • Peaked 3d ago at 1 mentions (2026-08-04); latest day: 1
  • 4 total mentions across 4 days

Deep dive

Activity timeline4 mentions / 4d
00111Mentions · 2026-08-04: 1Mentions · 2026-08-05: 1Mentions · 2026-08-07: 1Mentions · 2026-08-08: 1Patch / Workaround · 2026-08-04: 108-0408-0508-0708-08
Signal classification2 categories
General
375.0%
Disclosure
125.0%
Referenced assets1 URL
By indicator
Classification over time
DateTotalLabels
2026-08-041
General1
2026-08-051
General1
2026-08-071
General1
2026-08-081
Disclosure1
Full discourse4 posts
  • ケイ | IT・セキュリティ系副業Webライター@Teeeda_worker
    Disclosure

    CVE-2026-42331 FOSSBilling バージョン0.8.0以前の脆弱性をわかりやすく解説|影響範囲と対策まとめ https://www.cybernote.click/2026/08/03/cve-2026-42331-fossbilling-080/ #IT #Security #cybersecurity

    Post summary

    The post references CVE‑2026‑42331 affecting FOSSBilling <0.8.0 and promises a clear explanation of impact and countermeasures, but it provides no PoC, exploit code, or detailed technical information.

    0001063
    211 followersView on X
  • ケイ | IT・セキュリティ系副業Webライター@Teeeda_worker
    General

    CVE-2026-42331 FOSSBilling バージョン0.8.0以前の脆弱性をわかりやすく解説|影響範囲と対策まとめ https://www.cybernote.click/2026/08/03/cve-2026-42331-fossbilling-080/ #IT #Security #cybersecurity

    Post summary

    Article provides an overview of CVE‑2026‑42331 in FOSSBilling version 0.8.0 and earlier, summarizing impact and countermeasures, but contains no PoC, exploit, active exploitation claim, or patch details in the excerpt.

    0000041
    211 followersView on X
  • ケイ | IT・セキュリティ系副業Webライター@Teeeda_worker
    General

    CVE-2026-42331 FOSSBilling バージョン0.8.0以前の脆弱性をわかりやすく解説|影響範囲と対策まとめ https://www.cybernote.click/2026/08/03/cve-2026-42331-fossbilling-080/ #IT #Security #cybersecurity

    Post summary

    The article provides an overview of CVE‑2026‑42331 affecting FOSSBilling versions prior to 0.8.0 and summarizes the impact and general mitigation guidance.

    0000045
    211 followersView on X
  • ケイ | IT・セキュリティ系副業Webライター@Teeeda_worker
    General

    CVE-2026-42331 FOSSBilling バージョン0.8.0以前の脆弱性をわかりやすく解説|影響範囲と対策まとめ https://www.cybernote.click/2026/08/03/cve-2026-42331-fossbilling-080/ #IT #Security #cybersecurity

    Post summary

    The post announces CVE‑2026‑42331 affecting FOSSBilling versions before 0.8.0 and links to a Japanese article that explains the issue and summarizes impact and mitigation steps.

    0000039
    211 followersView on X

Explore more