CVE-2026-48777

CRITICALPre-NVD 9.39.3
EchelonGraph scoreMEDIUM confidence

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

This critical-severity CVE scores 9.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (46th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Elevated

Also known asEUVD-2026-37207 (ENISA EUVD) · GHSA-qqqm-5547-774x (GitHub Security Advisories) · GO-2026-5591 (OSV.dev)Source: ENISA EUVD

9.3EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (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: 0.5%CVSS: 9.3Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

FileBrowser Quantum is a free, self-hosted, web-based file manager. Versions prior to 1.3.2-stable, 1.4.0-beta and 1.4.1-beta are vulnerable to Path Traversal through the publicPatchHandler in backend/http/public.go which joins user-controlled fromPath and toPath body fields with the trusted d.share.Path BEFORE the downstream sanitizer runs. Because filepath.Join collapses .. segments during the join, the sanitizer in resourcePatchHandler never sees the traversal and the move/copy/rename operates on a path outside the shared directory. The same root-cause pattern was patched for the bulk DELETE endpoint as CVE-2026-44542 (GHSA-fwj3-42wh-8673), but the PATCH handler with the identical pattern was not updated. A public share link with AllowModify=true is sufficient to exploit this. Anyone holding such a link can move, copy, or rename arbitrary files within the share owner's source root. This issue has been fixed in versions 1.3.3-stable and 1.4.2-beta.

CVSS
9.3
EG Score
9.3CRITICALmedium confidence
EG Risk
73
EG Risk 73/100

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)
Severity93% × 45%
Impact severity (EG Severity): CVSS 9.3 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.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (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 at low or medium mission impact and sooner than that at high.
EPSS PROB
0.5%
EPSS %ILE
46th
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 (9.3): severity, escalated by confirmed exploitation. This CVE's 9.3 is its impact severity (EG Severity), not escalated.

EG Severity
9.3 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-13). 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, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (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)3 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (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

May 22, 2026

Last Modified

October 25, 2026

Advisory Details (3)

Auto-updated Oct 8, 2026
Patch available. Sources: github_release, github.
GitHub advisoryMentions a patch (unverified)

Path traversal in public share PATCH allows file ops outside shared directory · Advisory · gtsteffaniak/filebrowser · GitHub

https://github.com/gtsteffaniak/filebrowser/security/advisories/GHSA-qqqm-5547-774x
GitHub release Patch Available

v1.4.2-beta

Patch available: gtsteffaniak/filebrowser v1.4.2-beta (pre-release)

https://github.com/gtsteffaniak/filebrowser/releases/tag/v1.4.2-beta
GitHub release Patch Available

v1.3.3-stable

Patch available: gtsteffaniak/filebrowser v1.3.3-stable

https://github.com/gtsteffaniak/filebrowser/releases/tag/v1.3.3-stable

Vendor Advisories for CVE-2026-48777(1)

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

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
gogithub.com/gtsteffaniak/filebrowser/backend @ 0.0.0-20260518193514-28e9b81e438e (fixes < 0.0.0-20260518193514-28e9b81e438e)—ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFix by version rangeDependents
github.com/gtsteffaniak/filebrowser/backend—
  • every version up to 0.0.0-20260518193514-28e9b81e438e: fixed in 0.0.0-20260518193514-28e9b81e438e
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 44× 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 its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS → 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 220 rows 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 120 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 21:03 UTCEchelonGraph re-scored
  2. 2026-11-13 21:03 UTCGHSA enrichmentGHSA-qqqm-5547-774x · GitHub severity CRITICAL
  3. 2026-11-13 16:52 UTCEPSS rescoreEPSS 0.5% · 46th percentile
  4. 2026-11-12 17:50 UTCEchelonGraph re-scored
  5. 2026-11-12 17:50 UTCGHSA enrichmentGHSA-qqqm-5547-774x · GitHub severity CRITICAL
  6. 2026-11-12 16:34 UTCEPSS rescoreEPSS 0.5% · 46th percentile
  7. 2026-11-11 16:39 UTCEPSS rescoreEPSS 0.5% · 46th percentile
  8. 2026-11-11 15:55 UTCEchelonGraph re-scored
  9. 2026-11-11 15:55 UTCGHSA enrichmentGHSA-qqqm-5547-774x · GitHub severity CRITICAL
  10. 2026-11-10 16:44 UTCEPSS rescoreEPSS 0.5% · 46th percentile
  11. 2026-11-10 14:01 UTCEchelonGraph re-scored
  12. 2026-11-10 14:01 UTCGHSA enrichmentGHSA-qqqm-5547-774x · GitHub severity CRITICAL
  13. 2026-11-09 16:35 UTCEPSS rescoreEPSS 0.5% · 46th percentile
  14. 2026-11-09 12:07 UTCEchelonGraph re-scored
  15. 2026-11-09 12:07 UTCGHSA enrichmentGHSA-qqqm-5547-774x · GitHub severity CRITICAL
  16. 2026-11-08 16:39 UTCEPSS rescoreEPSS 0.5% · 46th percentile
  17. 2026-11-08 10:11 UTCEchelonGraph re-scored
  18. 2026-11-08 10:11 UTCGHSA enrichmentGHSA-qqqm-5547-774x · GitHub severity CRITICAL
  19. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.5% · 46th percentile
  20. 2026-11-07 08:11 UTCEchelonGraph re-scored
  21. 2026-11-07 08:11 UTCGHSA enrichmentGHSA-qqqm-5547-774x · GitHub severity CRITICAL
  22. 2026-11-06 16:38 UTCEPSS rescoreEPSS 0.5% · 46th percentile
  23. 2026-11-06 10:25 UTCOSV refresh
  24. 2026-11-06 06:17 UTCEchelonGraph re-scored
  25. 2026-11-06 06:17 UTCGHSA enrichmentGHSA-qqqm-5547-774x · GitHub severity CRITICAL
Show 75 more
  1. 2026-11-05 16:37 UTCEPSS rescoreEPSS 0.5% · 46th percentile
  2. 2026-11-05 04:23 UTCEchelonGraph re-scored
  3. 2026-11-05 04:23 UTCGHSA enrichmentGHSA-qqqm-5547-774x · GitHub severity CRITICAL
  4. 2026-11-04 16:35 UTCEPSS rescoreEPSS 0.5% · 46th percentile
  5. 2026-11-04 02:26 UTCEchelonGraph re-scored
  6. 2026-11-04 02:26 UTCGHSA enrichmentGHSA-qqqm-5547-774x · GitHub severity CRITICAL
  7. 2026-11-03 16:48 UTCEPSS rescoreEPSS 0.5% · 46th percentile
  8. 2026-11-03 00:32 UTCEchelonGraph re-scored
  9. 2026-11-03 00:32 UTCGHSA enrichmentGHSA-qqqm-5547-774x · GitHub severity CRITICAL
  10. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  11. 2026-11-01 22:38 UTCEchelonGraph re-scored
  12. 2026-11-01 22:38 UTCGHSA enrichmentGHSA-qqqm-5547-774x · GitHub severity CRITICAL
  13. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  14. 2026-11-01 07:46 UTCGHSA enrichmentGHSA-qqqm-5547-774x · GitHub severity CRITICAL
  15. 2026-10-31 20:43 UTCEchelonGraph re-scored
  16. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.5% · 46th percentile
  17. 2026-10-30 18:49 UTCEchelonGraph re-scored
  18. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  19. 2026-10-29 16:54 UTCEchelonGraph re-scored
  20. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  21. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  22. 2026-10-28 14:59 UTCEchelonGraph re-scored
  23. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  24. 2026-10-27 05:26 UTCEchelonGraph re-scored
  25. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  26. 2026-10-25 23:00 UTCEchelonGraph re-scored
  27. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  28. 2026-10-25 14:23 UTCEchelonGraph re-scored
  29. 2026-10-24 21:05 UTCEchelonGraph re-scored
  30. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  31. 2026-10-23 19:11 UTCEchelonGraph re-scored
  32. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  33. 2026-10-22 17:16 UTCEchelonGraph re-scored
  34. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  35. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  36. 2026-10-21 15:20 UTCEchelonGraph re-scored
  37. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  38. 2026-10-20 13:25 UTCEchelonGraph re-scored
  39. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  40. 2026-10-19 11:29 UTCEchelonGraph re-scored
  41. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  42. 2026-10-18 03:34 UTCEchelonGraph re-scored
  43. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  44. 2026-10-17 03:56 UTCEchelonGraph re-scored
  45. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  46. 2026-10-16 02:00 UTCEchelonGraph re-scored
  47. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  48. 2026-10-14 21:45 UTCEchelonGraph re-scored
  49. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  50. 2026-10-13 17:34 UTCEchelonGraph re-scored
  51. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  52. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  53. 2026-10-12 15:34 UTCEchelonGraph re-scored
  54. 2026-10-11 19:43 UTCEchelonGraph re-scored
  55. 2026-10-11 16:58 UTCEchelonGraph re-scored
  56. 2026-10-11 14:22 UTCEchelonGraph re-scored
  57. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  58. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  59. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  60. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  61. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  62. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  63. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  64. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  65. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  66. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  67. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  68. 2026-09-30 10:47 UTCOSV refresh
  69. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  70. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  71. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  72. 2026-09-26 00:27 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  73. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  74. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  75. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 38th percentile

Frequently asked(5)

What is CVE-2026-48777?
CVE-2026-48777 is a critical-severity vulnerability; its CVE record was published on May 22, 2026. FileBrowser Quantum is a free, self-hosted, web-based file manager. Versions prior to 1.3.2-stable, 1.4.0-beta and 1.4.1-beta are vulnerable to Path Traversal through the publicPatchHandler in backend/http/public.go which joins user-controlled fromPath and toPath body fields with the trusted…
When was the CVE record for CVE-2026-48777 published?
The CVE record for CVE-2026-48777 was published on May 22, 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 October 25, 2026; the record at its source may have been updated since.
Is CVE-2026-48777 actively exploited?
CVE-2026-48777 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (46th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-48777?
CVE-2026-48777 has a CVSS base score of 9.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-48777?
A fix for CVE-2026-48777 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-48777 are linked in the Vendor Advisories panel on this page.

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