CVE-2026-40568

HIGHNVD 8.58.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

This high-severity CVE scores 8.5 under NVD CVSS v3. EPSS exploit probability: 0.2% (14th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3
Elevated

Also known asEUVD-2026-24169 (ENISA EUVD)Source: ENISA EUVD

8.5EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 8.5Exploit: No code on recordExposed services: Not assessed

The CVE record names the fixed release — apply it.

FreeScout is a free self-hosted help desk and shared mailbox. Versions prior to 1.8.213 have a stored cross-site scripting (XSS) vulnerability in the mailbox signature feature. The sanitization function Helper::stripDangerousTags() (app/Misc/Helper.php:568) uses an incomplete blocklist of only four HTML tags (script, form, iframe, object) and does not remove event handler attributes. When a mailbox signature is saved via MailboxesController::updateSave() (app/Http/Controllers/MailboxesController.php:267), HTML elements such as `, , and with event handler attributes like onerror and onload pass through sanitization unchanged and are stored in the database. The signature is then rendered as raw HTML via the Blade {!! !!} tag in editor_bottom_toolbar.blade.php:6 and re-inserted into the visible DOM by jQuery .html() at main.js:1789-1790, triggering the injected event handlers. Any authenticated user with the ACCESS_PERM_SIGNATURE (sig`) permission on a mailbox -- a delegatable, non-admin permission -- can inject arbitrary HTML and JavaScript into the mailbox signature. The payload fires automatically, with no victim interaction, whenever any agent or administrator opens any conversation in the affected mailbox. This enables session hijacking (under CSP bypass conditions such as IE11 or module-weakened CSP), phishing overlays that work in all browsers regardless of CSP, and chaining to admin-level actions including email exfiltration via mass assignment and self-propagating worm behavior across all mailboxes. Version 1.8.213 fixes the issue.

CVSS v3
8.5
EG Score
8.5HIGHmedium confidence
EG Risk
54
EG Risk 54/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity85% × 45%
Impact severity (EG Severity): CVSS 8.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: The CVE record names the fixed release. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
14th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (8.5): severity, escalated by confirmed exploitation. This CVE's 8.5 is its impact severity (EG Severity), not escalated.

EG Severity
8.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS. FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

The CVE record names the fixed release. Apply it within your standard update timelines.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

April 21, 2026

Last Modified

April 22, 2026

Advisory Details (3)

Auto-updated May 4, 2026
Fix named in the CVE record. Sources: github.
GitHub advisoryMentions a patch (unverified)

XSS via Mailbox Signature Due to Incomplete HTML Sanitization · Advisory · freescout-help-desk/freescout · GitHub

https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-w2f5-6wcv-677r
Web page

Release 1.8.213 · freescout-help-desk/freescout · GitHub

https://github.com/freescout-help-desk/freescout/releases/tag/1.8.213
Web page

Add CheckBrowser middleware ensuring that browser supports CSP · freescout-help-desk/freescout@1d83e1c · GitHub

https://github.com/freescout-help-desk/freescout/commit/1d83e1cffb0bf8d109625313530b36b0f5910b3f

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 38× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 99 of 201 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 100 is merged into the row it repeats. The 102 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  2. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  3. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  4. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  5. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  6. 2026-10-25 14:30 UTCEG score recompute
  7. 2026-10-25 06:40 UTCEG score recompute
  8. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  9. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  10. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  11. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  12. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  13. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  14. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  15. 2026-10-18 03:42 UTCEG score recompute
  16. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  17. 2026-10-17 14:50 UTCEG score recompute
  18. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  19. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  20. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  21. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  22. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  23. 2026-10-12 16:09 UTCEG score recompute
  24. 2026-10-11 19:51 UTCEG score recompute
  25. 2026-10-11 17:05 UTCEG score recompute
Show 74 more
  1. 2026-10-11 14:31 UTCEG score recompute
  2. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  3. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  4. 2026-10-10 18:55 UTCOSV refresh
  5. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  6. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  7. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  8. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  9. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  10. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  11. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  12. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  13. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  14. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  15. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  16. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  17. 2026-09-21 05:49 UTCOSV refresh
  18. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  19. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  20. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  21. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  22. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  23. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  24. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  25. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  26. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  27. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  28. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  29. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  30. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  31. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  32. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  33. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  34. 2026-09-02 03:39 UTCOSV refresh
  35. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  36. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  37. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  38. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  39. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  40. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  41. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  42. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  43. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  44. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  45. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  46. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  47. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  48. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  49. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  50. 2026-08-16 06:17 UTCEG score recompute
  51. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  52. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  53. 2026-08-14 04:29 UTCEG score recompute
  54. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  55. 2026-08-12 18:40 UTCEG score recompute
  56. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  57. 2026-08-11 16:51 UTCEG score recompute
  58. 2026-08-11 13:43 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  59. 2026-08-11 02:26 UTCEG score recompute
  60. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  61. 2026-08-09 15:44 UTCEG score recompute
  62. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  63. 2026-08-09 03:41 UTCEG score recompute
  64. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  65. 2026-08-08 00:59 UTCEG score recompute
  66. 2026-08-07 12:57 UTCEG score recompute
  67. 2026-08-06 13:46 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  68. 2026-08-05 23:11 UTCEG score recompute
  69. 2026-08-05 19:17 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  70. 2026-08-04 15:10 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  71. 2026-08-04 10:38 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  72. 2026-08-02 12:47 UTCEG score recompute
  73. 2026-08-02 02:27 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  74. 2026-08-01 04:16 UTCEPSS rescoreEPSS 0.2% · 15th percentile

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-40568?
CVE-2026-40568 is a high-severity vulnerability; its CVE record was published on April 21, 2026. FreeScout is a free self-hosted help desk and shared mailbox. Versions prior to 1.8.213 have a stored cross-site scripting (XSS) vulnerability in the mailbox signature feature. The sanitization function Helper::stripDangerousTags() (app/Misc/Helper.php:568) uses an incomplete blocklist of only four…
When was the CVE record for CVE-2026-40568 published?
The CVE record for CVE-2026-40568 was published on April 21, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of April 22, 2026; the record at its source may have been updated since.
Is CVE-2026-40568 actively exploited?
CVE-2026-40568 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (14th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-40568?
CVE-2026-40568 has a CVSS v3 base score of 8.5 (NVD).
How do I remediate CVE-2026-40568?
The CVE record for CVE-2026-40568 names the fix: "Version 1.8.213 fixes the issue."

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