CVE-2026-55418

HIGHPre-NVD 8.68.6—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.6 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 78% 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, secondary
Trending — 3 sources updated this week
8.6
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.6Exploit: NoneExposed: 0

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

FastGPT is an open source AI knowledge base platform. Prior to v4.15.0-beta5, two FastGPT file handlers authorize an unrelated resource and then sign or read an S3 object using a key taken directly from the request, without checking that the key belongs to the caller's team. Because S3 object keys are global within the bucket and carry the tenant id only as a path segment, an attacker can supply another team's key and obtain its file contents through the chat-file presign endpoint or dataset preview endpoint. This issue is fixed in version v4.15.0-beta5.

CVSS v3
8.6
EG Score
8.6(medium)
EPSS
21.7%
KEV
Not listed

Published

July 7, 2026

Last Modified

July 9, 2026

Advisory Details (4)

Auto-updated Jul 7, 2026
🔬 Proof of concept available. Patch available. Sources: github_release, github, github_commit, github_pr.
github Patch Available🟡 PoC Available

S3 presign/read handlers do not bind the object key to the caller's team (cross-team file disclosure) · Advisory · labring/FastGPT · GitHub

https://github.com/labring/FastGPT/security/advisories/GHSA-6rxv-p43w-mmx5
github_release Patch Available

v4.15.0-beta5

Patch available: labring/FastGPT v4.15.0-beta5 (pre-release)

https://github.com/labring/FastGPT/releases/tag/v4.15.0-beta5
github_pr Patch Available

fix: bind S3 object keys to authorized resources

Patch available: labring/FastGPT v4.15.0-beta5 (PR #7104 merged 2026-06-12)

https://github.com/labring/FastGPT/pull/7104
github_commit Patch Available

commit decb6d2fb141 (labring/FastGPT)

Patch available: labring/FastGPT v4.15.0-beta5 (contains commit decb6d2fb141)

https://github.com/labring/FastGPT/commit/decb6d2fb1417fb9e2bca145d2dcc9cbcf06396c

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 21× in last 7d / 21× 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.

  1. 2026-07-13 06:13 UTCEPSS rescore
  2. 2026-07-13 06:13 UTCEPSS rescore
  3. 2026-07-13 02:33 UTCEG score recompute
  4. 2026-07-12 14:04 UTCEG score recompute
  5. 2026-07-12 05:46 UTCEPSS rescore
  6. 2026-07-12 01:33 UTCEG score recompute
  7. 2026-07-11 13:04 UTCEG score recompute
  8. 2026-07-11 08:27 UTCEPSS rescore
  9. 2026-07-11 08:27 UTCEPSS rescore
  10. 2026-07-11 00:33 UTCEG score recompute
  11. 2026-07-10 12:03 UTCEG score recompute
  12. 2026-07-09 23:33 UTCEG score recompute
  13. 2026-07-09 19:10 UTCEPSS rescore
  14. 2026-07-09 19:10 UTCEPSS rescore
  15. 2026-07-09 11:04 UTCEG score recompute
  16. 2026-07-08 22:35 UTCEG score recompute
  17. 2026-07-08 15:16 UTCEPSS rescore
  18. 2026-07-08 15:16 UTCEPSS rescore
  19. 2026-07-08 10:07 UTCEG score recompute
  20. 2026-07-07 21:37 UTCEG score recompute
  21. 2026-07-07 21:37 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-55418?
CVE-2026-55418 is a high vulnerability published on July 7, 2026. FastGPT is an open source AI knowledge base platform. Prior to v4.15.0-beta5, two FastGPT file handlers authorize an unrelated resource and then sign or read an S3 object using a key taken directly from the request, without checking that the key belongs to the caller's team. Because S3 object keys…
When was CVE-2026-55418 disclosed?
CVE-2026-55418 was first published in the National Vulnerability Database on July 7, 2026, with the most recent update on July 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55418 actively exploited?
CVE-2026-55418 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 21.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-55418?
CVE-2026-55418 has a CVSS v3 base score of 8.6 (NVD).
How do I remediate CVE-2026-55418?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55418, 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.

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