CVE-2026-103398

HIGHPre-NVD 8.18.1—
EchelonGraph scoreHIGH confidence

Score 8.1 from GitHub Security Advisory (severity: HIGH) published 2026-09-30. The CNA's CVSS baseline 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Trending — 4 sources updated this week
8.1EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 8.1Exploit: None knownExposed services: Not assessed

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

OpenSave through 2.4.0 fails to properly validate save paths supplied by paired peers in the manifest request handler. Attackers can specify arbitrary directories outside configured save locations to read and write files through manifest and sync routes.

CVSS v3
8.1
EG Score
8.1HIGHhigh confidence
EG Risk
37
EG Risk 37/100CISA SSVC

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
Severity81% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
EPSS PROB
0.3%
EPSS %ILE
17th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* at high (mission-essential systems).

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 30, 2026

Last Modified

October 1, 2026

Advisory Details (5)

Auto-updated Sep 30, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic

OpenSave through 2.4.0 Arbitrary File Read and Write via Peer-Controlled Save Path | Advisories | VulnCheck

https://www.vulncheck.com/advisories/opensave-through-2.4.0-arbitrary-file-read-and-write-via-peer-controlled-save-path
generic

GitHub - Liquid-co/OpenSave: Free, open-source, peer-to-peer game save sync — Steam Cloud for every game you own. No accounts, no telemetry · GitHub

https://github.com/Liquid-co/OpenSave
generic🔴 Active Exploitation

OpenSave/internal/delta/rootguard.go at v2.4.0 · Liquid-co/OpenSave · GitHub

https://github.com/Liquid-co/OpenSave/blob/v2.4.0/internal/delta/rootguard.go#L16-L30
generic

OpenSave/internal/p2p/routes.go at v2.4.0 · Liquid-co/OpenSave · GitHub

https://github.com/Liquid-co/OpenSave/blob/v2.4.0/internal/p2p/routes.go#L555-L566
generic

OpenSave: the WAN sync path does not authenticate the sender, and a peer chooses the save root (CWE-290, CWE-73) · GitHub

https://gist.github.com/mansurmavlankulov/2ca66f95965fb9d4aab353bcf2434cdb

Vendor Advisories for CVE-2026-103398(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 22× in last 7d / 22× 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. 2026-10-04 08:12 UTCGHSA enrichment
  2. 2026-10-03 19:11 UTCEG score recompute
  3. 2026-10-03 19:11 UTCGHSA enrichment
  4. 2026-10-03 14:25 UTCEPSS rescore
  5. 2026-10-03 06:10 UTCGHSA enrichment
  6. 2026-10-02 17:08 UTCEG score recompute
  7. 2026-10-02 17:08 UTCGHSA enrichment
  8. 2026-10-02 04:07 UTCEG score recompute
  9. 2026-10-02 04:06 UTCGHSA enrichment
  10. 2026-10-01 19:49 UTCEPSS rescore
  11. 2026-10-01 15:02 UTCEG score recompute
  12. 2026-10-01 15:01 UTCGHSA enrichment
  13. 2026-10-01 06:49 UTCGHSA enrichment
  14. 2026-09-30 17:45 UTCGHSA enrichment
  15. 2026-09-30 16:22 UTCEG score recompute
  16. 2026-09-30 16:22 UTCGHSA enrichment
  17. 2026-09-30 15:53 UTCEG score recompute
  18. 2026-09-30 15:53 UTCGHSA enrichment
  19. 2026-09-30 15:37 UTCEG score recompute
  20. 2026-09-30 15:37 UTCGHSA enrichment
  21. 2026-09-30 14:52 UTCEG score recompute
  22. 2026-09-30 14:52 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-103398?
CVE-2026-103398 is a high vulnerability published on September 30, 2026. OpenSave through 2.4.0 fails to properly validate save paths supplied by paired peers in the manifest request handler. Attackers can specify arbitrary directories outside configured save locations to read and write files through manifest and sync routes.
When was CVE-2026-103398 disclosed?
CVE-2026-103398 was first published on September 30, 2026, with the most recent update on October 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-103398 actively exploited?
CVE-2026-103398 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (17th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-103398?
CVE-2026-103398 has a CVSS base score of 8.1 (the CNA's own assessment, by vulncheck; NVD's own analysis pending).
How do I remediate CVE-2026-103398?
No fix for CVE-2026-103398 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-103398 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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