CVE-2026-76838

HIGHPre-NVD 8.58.5
EchelonGraph scoreMEDIUM confidence

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

Score 8.5 from GitHub Security Advisory (severity: HIGH) published 2026-08-24. A secondary CVSS source baseline 8.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 3 sources updated this week
8.5EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 8.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Hi.Events validates a webhook destination only when it is registered, never when it is used. NoInternalUrlRule in backend/app/Validators/Rules/NoInternalUrlRule.php resolves the hostname with gethostbyname() and rejects private and reserved ranges, which any public hostname passes. At dispatch, WebhookDispatchService takes the stored URL and calls it through spatie/laravel-webhook-server without repeating the check, and backend/config/webhook-server.php sets no Guzzle options, so redirect following remains enabled by default. A destination that answers with a redirect to a loopback, private or cloud metadata address therefore causes the server to issue that request, and changing the hostname's DNS record after registration reaches the same result because no resolution is repeated. The response is not discarded: WebhookResponseHandlerService stores the body on the webhook log and WebhookLogResource returns it from the webhook logs endpoint, so the requester reads what the internal service replied rather than inferring it. Both event and organizer webhooks share the rule and the dispatch path. Version 1.11.1-beta revalidates at dispatch, pins the validated address, checks every redirect hop, and decodes IPv6 transition addresses that previously bypassed the filter.

CVSS v3
8.5
EG Score
8.5HIGHmedium confidence
EG Risk
38
EG Risk 38/100

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 (value × EchelonGraph’s weight)
Severity85% × 45%
The EG Score, 8.5 of 10.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (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: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.4%
EPSS %ILE
34th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (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

August 24, 2026

Last Modified

October 12, 2026

Advisory Details (5)

Auto-updated Aug 24, 2026
Patch available. Sources: github_commit, github_pr.
Web page

Hi.Events before 1.11.1-beta Server-Side Request Forgery via Unvalidated Webhook Redirects | Advisories | VulnCheck

https://www.vulncheck.com/advisories/hi-events-before-beta-server-side-request-forgery-via-unvalidated-webhook-redirects
Web page

Hi.Events/backend/app/Validators/Rules/NoInternalUrlRule.php at v.1.11.0-beta · HiEventsDev/Hi.Events · GitHub

https://github.com/HiEventsDev/Hi.Events/blob/v.1.11.0-beta/backend/app/Validators/Rules/NoInternalUrlRule.php
GitHub commit Patch Available

commit cfbf468bb5b1 (HiEventsDev/Hi.Events)

Patch available: HiEventsDev/Hi.Events v1.11.1-beta (contains commit cfbf468bb5b1)

https://github.com/HiEventsDev/Hi.Events/commit/cfbf468bb5b1
GitHub pull request Patch Available

Fix reported security advisories

Patch available: HiEventsDev/Hi.Events v1.11.1-beta (PR #1311 merged 2026-08-11)

https://github.com/HiEventsDev/Hi.Events/pull/1311
Web page

GitHub - HiEventsDev/Hi.Events: Open-source event management and ticket selling platform — perfect for concerts, conferences, and everything in between 🎟️ If you find this project helpful, please consider giving us a star ⭐️ · GitHub

https://github.com/HiEventsDev/Hi.Events

Vendor Advisories for CVE-2026-76838(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 18× in last 7d / 102× 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 100 of 188 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. None are among the latest 100 rows. The 88 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  2. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  3. 2026-10-12 15:26 UTCEG score recompute
  4. 2026-10-12 15:26 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  5. 2026-10-11 19:23 UTCEG score recompute
  6. 2026-10-11 16:39 UTCEG score recompute
  7. 2026-10-11 13:58 UTCEG score recompute
  8. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  9. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  10. 2026-10-10 12:33 UTCEG score recompute
  11. 2026-10-10 12:32 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  12. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  13. 2026-10-09 04:46 UTCEG score recompute
  14. 2026-10-09 04:46 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  15. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  16. 2026-10-08 03:50 UTCEG score recompute
  17. 2026-10-08 03:50 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  18. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  19. 2026-10-07 06:54 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  20. 2026-10-06 19:20 UTCEG score recompute
  21. 2026-10-06 19:19 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  22. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  23. 2026-10-06 07:45 UTCEG score recompute
  24. 2026-10-06 07:45 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  25. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 34th percentile
Show 75 more
  1. 2026-10-05 17:04 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  2. 2026-10-05 04:45 UTCEG score recompute
  3. 2026-10-05 04:45 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  4. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  5. 2026-10-04 15:40 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  6. 2026-10-04 04:06 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  7. 2026-10-03 16:31 UTCEG score recompute
  8. 2026-10-03 16:31 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  9. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  10. 2026-10-02 20:58 UTCEG score recompute
  11. 2026-10-02 20:58 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  12. 2026-10-02 08:36 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  13. 2026-10-01 21:02 UTCEG score recompute
  14. 2026-10-01 21:02 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  15. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  16. 2026-10-01 07:52 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  17. 2026-09-30 20:17 UTCEG score recompute
  18. 2026-09-30 20:17 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  19. 2026-09-30 07:00 UTCEG score recompute
  20. 2026-09-30 07:00 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  21. 2026-09-29 15:24 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  22. 2026-09-29 15:10 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  23. 2026-09-28 23:22 UTCEG score recompute
  24. 2026-09-28 23:22 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  25. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  26. 2026-09-28 11:27 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  27. 2026-09-27 23:53 UTCEG score recompute
  28. 2026-09-27 23:53 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  29. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  30. 2026-09-27 11:59 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  31. 2026-09-27 00:03 UTCEG score recompute
  32. 2026-09-27 00:03 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  33. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  34. 2026-09-26 00:28 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  35. 2026-09-25 06:41 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  36. 2026-09-24 19:07 UTCEG score recompute
  37. 2026-09-24 19:07 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  38. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  39. 2026-09-24 07:33 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  40. 2026-09-23 19:58 UTCEG score recompute
  41. 2026-09-23 19:58 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  42. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  43. 2026-09-23 06:57 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  44. 2026-09-22 19:22 UTCEG score recompute
  45. 2026-09-22 19:22 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  46. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  47. 2026-09-22 07:09 UTCEG score recompute
  48. 2026-09-22 07:09 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  49. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  50. 2026-09-21 19:34 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  51. 2026-09-21 07:57 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  52. 2026-09-20 20:23 UTCEG score recompute
  53. 2026-09-20 20:22 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  54. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  55. 2026-09-20 08:47 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  56. 2026-09-19 20:43 UTCEG score recompute
  57. 2026-09-19 20:43 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  58. 2026-09-19 09:09 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  59. 2026-09-18 21:34 UTCEG score recompute
  60. 2026-09-18 21:34 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  61. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  62. 2026-09-18 08:46 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  63. 2026-09-17 21:12 UTCEG score recompute
  64. 2026-09-17 21:12 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  65. 2026-09-17 09:09 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  66. 2026-09-16 21:35 UTCEG score recompute
  67. 2026-09-16 21:35 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  68. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  69. 2026-09-16 09:27 UTCEG score recompute
  70. 2026-09-16 09:27 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  71. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  72. 2026-09-15 21:02 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  73. 2026-09-15 08:49 UTCEG score recompute
  74. 2026-09-15 08:49 UTCGHSA enrichmentGHSA-j9wc-mrp3-532h · GitHub severity HIGH · GitHub CVSS 8.5
  75. 2026-09-15 03:12 UTCEPSS rescoreEPSS 0.3% · 23rd percentile

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-76838?
CVE-2026-76838 is a high-severity vulnerability; its CVE record was published on August 24, 2026. Hi.Events validates a webhook destination only when it is registered, never when it is used. NoInternalUrlRule in backend/app/Validators/Rules/NoInternalUrlRule.php resolves the hostname with gethostbyname() and rejects private and reserved ranges, which any public hostname passes. At dispatch,…
When was CVE-2026-76838 made public?
CVE-2026-76838 was made public on August 11, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on August 24, 2026. EchelonGraph's copy of the record carries a last-modified date of October 12, 2026; the record at its source may have been updated since.
Is CVE-2026-76838 actively exploited?
CVE-2026-76838 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (34th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-76838?
CVE-2026-76838 has a CVSS base score of 8.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-76838?
A fix for CVE-2026-76838 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-76838 are linked in the Vendor Advisories panel on this page.

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