CVE-2026-77763

MEDIUMPre-NVD 6.56.5
EchelonGraph scoreMEDIUM confidence

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

Score 6.5 from GitHub Security Advisory (severity: HIGH) published 2026-08-21. A secondary CVSS source baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source

Also known asEUVD-2026-63899 (ENISA EUVD) · GHSA-2pgv-c2r7-f43r (GitHub Security Advisories)Source: ENISA EUVD

6.5EG
EchelonGraph verdictMonitorThe upstream fix is not in a release yet: until the release ships, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule, then apply it (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 6.5Exploit: None knownExposed services: Not assessed

An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.

The filestore backend in pkg/object/file.go, used for file:// stores and as a common juicefs sync destination, derived every operation's target from path(key), which returned either filepath.Join(d.root, key) or filepath.Clean(d.root + key) with no check that the result stayed beneath the root. Put, Get, Head, Delete, Chmod, Chown, Symlink and Readlink all consumed that value directly. Object keys enumerated from a source object store during a sync are not constrained the way local filesystem names are, so a key containing traversal segments causes juicefs to write attacker-supplied content to a path outside the intended local destination, and no error is returned. An operator syncing from a bucket whose contents they do not fully control, such as a shared or public bucket or one an attacker can write to, is therefore exposed to a file write at an attacker-influenced location. The fix changes path() to return an error and rejects any key whose resolved path escapes the root.

CVSS v3
6.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
29
EG Risk 29/100

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)
Severity65% × 45%
Impact severity (EG Severity): CVSS 6.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.5% × 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: An upstream fix is merged but not yet in a tagged release. Until the release ships, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule, then apply it.
EPSS PROB
0.5%
EPSS %ILE
42nd
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 (6.5): severity, escalated by confirmed exploitation. This CVE's 6.5 is its impact severity (EG Severity), not escalated.

EG Severity
6.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). 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 every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.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 every mission impact level.

An upstream fix is merged but not yet in a tagged release. Until the release ships, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule, then apply it.

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.

No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.

The score's inputs: 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 21, 2026

Last Modified

October 16, 2026

Advisory Details (6)

Auto-updated Aug 21, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit, github_pr.
Web page

JuiceFS Local Filestore Backend Joins Object Keys onto the Storage Root Without a Containment Check, Allowing Writes Outside the Configured Directory | Advisories | VulnCheck

https://www.vulncheck.com/advisories/juicefs-local-filestore-backend-joins-object-keys-onto-the-storage-root-without-a-containment-check-allowing-writes-outside-the-configured-directory
GitHub pull request

object/file: reject object keys that escape the filestore root

Fix merged in juicedata/juicefs PR #7425 on 2026-08-21 — awaiting tagged release

https://github.com/juicedata/juicefs/pull/7425
Web page

Local filestore object backend writes outside its configured root via a crafted object key · Issue #7401 · juicedata/juicefs · GitHub

https://github.com/juicedata/juicefs/issues/7401
GitHub commit

commit 0bcd70b3d130 (juicedata/juicefs)

Fix landed in juicedata/juicefs commit 0bcd70b3d130 — awaiting tagged release

https://github.com/juicedata/juicefs/commit/0bcd70b3d13088d38127d6fb5750c91be7c4ec16
Web page

juicefs/pkg/object/file.go at v1.4.1 · juicedata/juicefs · GitHub

https://github.com/juicedata/juicefs/blob/v1.4.1/pkg/object/file.go
Web page

GitHub - juicedata/juicefs: JuiceFS is a distributed POSIX file system built on top of Redis and S3. · GitHub

https://github.com/juicedata/juicefs

Vendor Advisories for CVE-2026-77763(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 8× in last 7d / 53× 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 170 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 70 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  3. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  4. 2026-10-30 04:55 UTCOSV refresh
  5. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  6. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  7. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  8. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  9. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  10. 2026-10-25 14:01 UTCEG score recompute
  11. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  12. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  13. 2026-10-22 18:20 UTCEG score recompute
  14. 2026-10-22 18:20 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  15. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  16. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  17. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  18. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  19. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  20. 2026-10-18 03:11 UTCEG score recompute
  21. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  22. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  23. 2026-10-16 15:27 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  24. 2026-10-16 13:33 UTCEG score recompute
  25. 2026-10-16 13:33 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
Show 75 more
  1. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  2. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  3. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  4. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  5. 2026-10-12 15:37 UTCEG score recompute
  6. 2026-10-11 19:23 UTCEG score recompute
  7. 2026-10-11 16:39 UTCEG score recompute
  8. 2026-10-11 13:57 UTCEG score recompute
  9. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  10. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  11. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  12. 2026-10-09 06:01 UTCEG score recompute
  13. 2026-10-09 06:01 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  14. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  15. 2026-10-08 04:58 UTCEG score recompute
  16. 2026-10-08 04:58 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  17. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  18. 2026-10-06 21:18 UTCEG score recompute
  19. 2026-10-06 21:18 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  20. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  21. 2026-10-05 20:52 UTCEG score recompute
  22. 2026-10-05 20:52 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  23. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  24. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  25. 2026-10-04 20:49 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  26. 2026-10-03 16:43 UTCEG score recompute
  27. 2026-10-03 16:43 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  28. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  29. 2026-10-02 08:04 UTCEG score recompute
  30. 2026-10-02 08:04 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  31. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  32. 2026-10-01 08:01 UTCEG score recompute
  33. 2026-10-01 08:01 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  34. 2026-09-30 07:57 UTCEG score recompute
  35. 2026-09-30 07:57 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  36. 2026-09-29 15:24 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  37. 2026-09-29 02:42 UTCEG score recompute
  38. 2026-09-29 02:42 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  39. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  40. 2026-09-28 02:38 UTCEG score recompute
  41. 2026-09-28 02:38 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  42. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  43. 2026-09-27 02:32 UTCEG score recompute
  44. 2026-09-27 02:32 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  45. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  46. 2026-09-26 00:28 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  47. 2026-09-24 21:21 UTCEG score recompute
  48. 2026-09-24 21:21 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  49. 2026-09-24 14:58 UTCEG score recompute
  50. 2026-09-24 14:58 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  51. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  52. 2026-09-24 03:57 UTCEG score recompute
  53. 2026-09-24 03:57 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  54. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  55. 2026-09-23 03:51 UTCEG score recompute
  56. 2026-09-23 03:51 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  57. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  58. 2026-09-22 03:47 UTCEG score recompute
  59. 2026-09-22 03:47 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  60. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  61. 2026-09-21 03:42 UTCEG score recompute
  62. 2026-09-21 03:42 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  63. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  64. 2026-09-20 03:38 UTCEG score recompute
  65. 2026-09-20 03:38 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  66. 2026-09-19 03:34 UTCEG score recompute
  67. 2026-09-19 03:34 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  68. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  69. 2026-09-18 03:31 UTCEG score recompute
  70. 2026-09-18 03:31 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  71. 2026-09-17 03:27 UTCEG score recompute
  72. 2026-09-17 03:27 UTCGHSA enrichmentGHSA-2pgv-c2r7-f43r · GitHub severity HIGH · GitHub CVSS 6.5
  73. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  74. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  75. 2026-09-16 03:03 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-77763?
CVE-2026-77763 is a medium-severity vulnerability; its CVE record was published on August 21, 2026. The filestore backend in pkg/object/file.go, used for file:// stores and as a common juicefs sync destination, derived every operation's target from path(key), which returned either filepath.Join(d.root, key) or filepath.Clean(d.root + key) with no check that the result stayed beneath the root.…
When was CVE-2026-77763 made public?
CVE-2026-77763 was made public on August 15, 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 21, 2026. EchelonGraph's copy of the record carries a last-modified date of October 16, 2026; the record at its source may have been updated since.
Is CVE-2026-77763 actively exploited?
CVE-2026-77763 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (42nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-77763?
CVE-2026-77763 has a CVSS base score of 6.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-77763?
An upstream fix for CVE-2026-77763 has been merged but is not yet in a tagged release. Until it ships, restrict network exposure of the affected system or apply the vendor's mitigation, then update to the release that contains the fix. The vendor advisories EchelonGraph has for CVE-2026-77763 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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