CVE-2026-28289

HIGHNVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.1 under NVD CVSS v3. EPSS exploit probability: 31.1%, top 2% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Weaponized
8.1EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • Public exploit code is available (Metasploit, epss top5pct, public exploit)
CISA-KEV: Not listedEPSS PROB: 31%CVSS: 8.1Exploit: Metasploit · epss top5pct · public exploitExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. A patch bypass vulnerability for CVE-2026-27636 in FreeScout 1.8.206 and earlier allows any authenticated user with file upload permissions to achieve Remote Code Execution (RCE) on the server by uploading a malicious .htaccess file using a zero-width space character prefix to bypass the security check. The vulnerability exists in the sanitizeUploadedFileName() function in app/Http/Helper.php. The function contains a Time-of-Check to Time-of-Use (TOCTOU) flaw where the dot-prefix check occurs before sanitization removes invisible characters. This vulnerability is fixed in 1.8.207.

CVSS v3
8.1
EG Score
8.1(medium)
EG Risk
77(Track)
EG Risk 77/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity81% × 45%
Exploitation65% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
31%
EPSS %ILE
98%
KEV
Not listed

Published

March 3, 2026

Last Modified

June 17, 2026

Advisory Details (2)

Auto-updated Jul 27, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
github_commit Patch Available

commit f7bc16c56a6b (freescout-help-desk/freescout)

Patch available: freescout-help-desk/freescout 1.8.207 (contains commit f7bc16c56a6b)

https://github.com/freescout-help-desk/freescout/commit/f7bc16c56a6b13c06da52ad51fd666546b40818f
github Patch Available🟡 PoC Available

FreeScout 1.8.206 - Patch Bypass for CVE-2026-27636 via Zero-Width Space Character Leads to Unauthenticated Remote Code Execution · Advisory · freescout-help-desk/freescout · GitHub

https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-5gpc-65p8-ffwp

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 6× in last 7d / 27× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-19 13:33 UTCOSV refresh
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-18 19:27 UTCEPSS rescore
  4. 2026-09-17 19:30 UTCEPSS rescore
  5. 2026-09-16 14:08 UTCEPSS rescore
  6. 2026-09-16 05:15 UTCEPSS rescore
  7. 2026-09-12 15:01 UTCEPSS rescore
  8. 2026-09-11 14:52 UTCEPSS rescore
  9. 2026-09-10 09:34 UTCEPSS rescore
  10. 2026-09-08 22:00 UTCEPSS rescore
  11. 2026-09-06 13:47 UTCEPSS rescore
  12. 2026-09-06 13:47 UTCEPSS rescore
  13. 2026-09-04 05:06 UTCEPSS rescore
  14. 2026-09-02 14:11 UTCEPSS rescore
  15. 2026-09-01 13:53 UTCEPSS rescore
  16. 2026-09-01 04:39 UTCEPSS rescore
  17. 2026-09-01 04:39 UTCEPSS rescore
  18. 2026-08-31 17:34 UTCOSV refresh
  19. 2026-08-30 19:17 UTCEPSS rescore
  20. 2026-08-30 01:22 UTCEPSS rescore
  21. 2026-08-28 21:41 UTCEPSS rescore
  22. 2026-08-27 14:25 UTCEPSS rescore
  23. 2026-08-26 14:46 UTCEPSS rescore
  24. 2026-08-25 13:49 UTCEPSS rescore
  25. 2026-08-24 14:17 UTCEPSS rescore
Show 31 more
  1. 2026-08-23 00:19 UTCEPSS rescore
  2. 2026-08-21 23:49 UTCEPSS rescore
  3. 2026-08-20 22:55 UTCEPSS rescore
  4. 2026-08-20 22:55 UTCEPSS rescore
  5. 2026-08-19 17:03 UTCEPSS rescore
  6. 2026-08-18 13:48 UTCEPSS rescore
  7. 2026-08-17 13:47 UTCEPSS rescore
  8. 2026-08-16 14:56 UTCEPSS rescore
  9. 2026-08-16 02:14 UTCEPSS rescore
  10. 2026-08-15 01:30 UTCEPSS rescore
  11. 2026-08-14 08:39 UTCEG score recompute
  12. 2026-08-13 22:00 UTCEPSS rescore
  13. 2026-08-13 00:28 UTCEG score recompute
  14. 2026-08-12 13:50 UTCEPSS rescore
  15. 2026-08-11 23:20 UTCEG score recompute
  16. 2026-08-11 13:42 UTCEPSS rescore
  17. 2026-08-09 08:16 UTCEG score recompute
  18. 2026-08-08 16:37 UTCEPSS rescore
  19. 2026-08-07 20:10 UTCEG score recompute
  20. 2026-08-06 13:46 UTCEPSS rescore
  21. 2026-08-06 02:44 UTCEG score recompute
  22. 2026-08-05 19:17 UTCEPSS rescore
  23. 2026-08-04 15:10 UTCEPSS rescore
  24. 2026-08-02 19:04 UTCEG score recompute▼ 1.90
  25. 2026-08-02 02:26 UTCEPSS rescore
  26. 2026-08-01 04:16 UTCEPSS rescore
  27. 2026-07-30 16:27 UTCEPSS rescore
  28. 2026-07-30 01:30 UTCEPSS rescore
  29. 2026-07-28 15:36 UTCEPSS rescore
  30. 2026-07-27 12:54 UTCEG score recompute
  31. 2026-07-27 12:50 UTCOSV refresh

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 Metasploit module). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Metasploitexploit/multi/http/freescout_htaccess_rce✓ verified
    First seen Mar 1, 2026

    FreeScout Unauthenticated RCE via ZWSP .htaccess Bypass

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-28289?
CVE-2026-28289 is a high vulnerability published on March 3, 2026. FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. A patch bypass vulnerability for CVE-2026-27636 in FreeScout 1.8.206 and earlier allows any authenticated user with file upload permissions to achieve Remote Code Execution (RCE) on the server by uploading a…
When was CVE-2026-28289 disclosed?
CVE-2026-28289 was first published in the National Vulnerability Database on March 3, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-28289 actively exploited?
CVE-2026-28289 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 31% probability of exploitation in the next 30 days, which ranks it in the top 1.8% of all scored CVEs.
What is the CVSS score of CVE-2026-28289?
CVE-2026-28289 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2026-28289?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-28289, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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