CVE-2026-42608

CRITICALNVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.5%, top 60% 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
Elevated
9.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 9.1Exploit: NoneExposed: 0

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

Grav is a file-based Web platform. Prior to 2.0.0-beta.2, there is a Path Traversal vulnerability within the FormFlash core component. By manipulating the session_id (passed as __form-flash-id in POST requests), an unauthenticated attacker can traverse the filesystem to create arbitrary directories and write an index.yaml file containing attacker-controlled data. This vulnerability can lead to unauthorized modification of application behavior, potential data integrity issues, and service disruption in production environments. This vulnerability is fixed in 2.0.0-beta.2.

CVSS v3
9.1
EG Score
9.1(medium)
EPSS
40.6%
KEV
Not listed

Published

May 11, 2026

Last Modified

May 13, 2026

Advisory Details (1)

Auto-updated May 11, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

[ZERO-DAY] Unauthenticated Path Traversal & Arbitrary File Write in FormFlash component. · Advisory · getgrav/grav · GitHub

https://github.com/getgrav/grav/security/advisories/GHSA-hmcx-ch82-3fv2

Affected Packages

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFixed inDependents
getgrav/grav0.8.0 ... 2.0.0-beta.1 (317 versions)2.0.0-beta.2—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 57× 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.

Showing the most recent 100 of 153 total refreshes for this CVE.

  1. 2026-07-11 08:27 UTCEPSS rescore
  2. 2026-07-09 19:10 UTCEPSS rescore
  3. 2026-07-08 15:15 UTCEPSS rescore
  4. 2026-07-07 13:46 UTCEPSS rescore
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  11. 2026-07-01 15:06 UTCEPSS rescore
  12. 2026-06-30 23:22 UTCEPSS rescore
  13. 2026-06-29 14:06 UTCEPSS rescore
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  15. 2026-06-28 08:50 UTCEG score recompute
  16. 2026-06-28 04:56 UTCEPSS rescore
  17. 2026-06-28 03:25 UTCEG score recompute
  18. 2026-06-27 14:18 UTCEG score recompute
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  20. 2026-06-27 03:08 UTCEPSS rescore
  21. 2026-06-26 21:07 UTCEG score recompute
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  23. 2026-06-25 13:49 UTCEPSS rescore
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  25. 2026-06-24 14:05 UTCEPSS rescore
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  1. 2026-06-23 21:33 UTCEPSS rescore
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  4. 2026-06-21 14:56 UTCEPSS rescore
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  6. 2026-06-21 01:59 UTCEPSS rescore
  7. 2026-06-19 19:25 UTCEPSS rescore
  8. 2026-06-18 17:52 UTCEPSS rescore
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  10. 2026-06-17 17:53 UTCEPSS rescore
  11. 2026-06-17 05:30 UTCEG score recompute
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  13. 2026-06-16 17:52 UTCEPSS rescore
  14. 2026-06-16 12:00 UTCEG score recompute
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  16. 2026-06-15 17:49 UTCEPSS rescore
  17. 2026-06-15 04:34 UTCEG score recompute
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  19. 2026-06-14 19:45 UTCEG score recompute
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  22. 2026-06-14 06:42 UTCEG score recompute
  23. 2026-06-14 01:59 UTCEG score recompute
  24. 2026-06-13 23:00 UTCEPSS rescore
  25. 2026-06-13 08:25 UTCEG score recompute
  26. 2026-06-12 23:12 UTCEPSS rescore
  27. 2026-06-12 23:12 UTCEPSS rescore
  28. 2026-06-12 22:43 UTCEG score recompute
  29. 2026-06-12 17:58 UTCEG score recompute
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  35. 2026-06-11 14:00 UTCEPSS rescore
  36. 2026-06-11 13:45 UTCEG score recompute
  37. 2026-06-11 09:24 UTCEG score recompute
  38. 2026-06-11 05:03 UTCEG score recompute
  39. 2026-06-11 00:42 UTCEG score recompute
  40. 2026-06-10 22:18 UTCEPSS rescore
  41. 2026-06-10 20:22 UTCEG score recompute
  42. 2026-06-10 16:01 UTCEG score recompute
  43. 2026-06-10 13:22 UTCEPSS rescore
  44. 2026-06-10 13:22 UTCEPSS rescore
  45. 2026-06-10 11:40 UTCEG score recompute
  46. 2026-06-10 07:20 UTCEG score recompute
  47. 2026-06-10 02:56 UTCEG score recompute
  48. 2026-06-09 22:35 UTCEG score recompute
  49. 2026-06-09 18:12 UTCEG score recompute
  50. 2026-06-09 13:51 UTCEG score recompute
  51. 2026-06-09 09:31 UTCEG score recompute
  52. 2026-06-09 05:09 UTCEG score recompute
  53. 2026-06-09 00:48 UTCEG score recompute
  54. 2026-06-08 20:27 UTCEG score recompute
  55. 2026-06-08 14:17 UTCEPSS rescore
  56. 2026-06-08 14:17 UTCEPSS rescore
  57. 2026-06-08 13:06 UTCEG score recompute
  58. 2026-06-08 08:46 UTCEG score recompute
  59. 2026-06-08 04:25 UTCEG score recompute
  60. 2026-06-08 00:04 UTCEG score recompute
  61. 2026-06-07 19:43 UTCEG score recompute
  62. 2026-06-07 15:25 UTCEPSS rescore
  63. 2026-06-07 15:25 UTCEPSS rescore
  64. 2026-06-07 15:23 UTCEG score recompute
  65. 2026-06-07 11:02 UTCEG score recompute
  66. 2026-06-07 06:42 UTCEG score recompute
  67. 2026-06-07 02:21 UTCEG score recompute
  68. 2026-06-06 22:00 UTCEG score recompute
  69. 2026-06-06 17:39 UTCEG score recompute
  70. 2026-06-06 13:47 UTCEPSS rescore
  71. 2026-06-06 13:47 UTCEPSS rescore
  72. 2026-06-06 13:18 UTCEG score recompute
  73. 2026-06-06 08:57 UTCEG score recompute
  74. 2026-06-06 04:36 UTCEG score recompute
  75. 2026-06-06 00:15 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-42608?
CVE-2026-42608 is a critical vulnerability published on May 11, 2026. Grav is a file-based Web platform. Prior to 2.0.0-beta.2, there is a Path Traversal vulnerability within the FormFlash core component. By manipulating the sessionid (passed as _form-flash-id in POST requests), an unauthenticated attacker can traverse the filesystem to create arbitrary directories…
When was CVE-2026-42608 disclosed?
CVE-2026-42608 was first published in the National Vulnerability Database on May 11, 2026, with the most recent update on May 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42608 actively exploited?
CVE-2026-42608 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 40.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-42608?
CVE-2026-42608 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-42608?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42608, 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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