CVE-2026-40541

CRITICALPre-NVD 9.09.0—
EchelonGraph scoreHIGH confidence

Score 9.0 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-28. a secondary CVSS source baseline 9.0; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
9.0EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.0Exploit: None knownExposed: 0

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

An improper neutralization of input during web page generation ('Cross-site Scripting') vulnerability in extract domain in Synology Chat Server before 2.4.5-22148 allows remote authenticated users, via a UI interaction, to read or write arbitrary files and conduct denial-of-service attacks in DSM.

CVSS v3
9.0
EG Score
9.0(high)
EG Risk
41(Track)
EG Risk 41/100SSVC: Track

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
Severity90% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
39%
KEV
Not listed

Published

August 28, 2026

Last Modified

August 28, 2026

Advisory Details (1)

Auto-updated Aug 28, 2026
No patch confirmed yet.
generic

Synology_SA_26_10 | Synology Inc.

https://www.synology.com/en-global/security/advisory/Synology_SA_26_10

Vendor Advisories for CVE-2026-40541(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 19× in last 7d / 19× 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. 2026-08-30 03:14 UTCEG score recompute
  2. 2026-08-30 03:14 UTCGHSA enrichment
  3. 2026-08-30 01:22 UTCEPSS rescore
  4. 2026-08-29 23:19 UTCGHSA enrichment
  5. 2026-08-29 19:24 UTCGHSA enrichment
  6. 2026-08-29 15:30 UTCGHSA enrichment
  7. 2026-08-29 11:35 UTCGHSA enrichment
  8. 2026-08-29 07:40 UTCGHSA enrichment
  9. 2026-08-29 03:46 UTCGHSA enrichment
  10. 2026-08-28 23:51 UTCEG score recompute
  11. 2026-08-28 23:50 UTCGHSA enrichment
  12. 2026-08-28 21:41 UTCEPSS rescore
  13. 2026-08-28 16:22 UTCEG score recompute
  14. 2026-08-28 16:22 UTCGHSA enrichment
  15. 2026-08-28 12:21 UTCEG score recompute
  16. 2026-08-28 12:21 UTCGHSA enrichment
  17. 2026-08-28 08:25 UTCEG score recompute
  18. 2026-08-28 07:33 UTCEG score recompute
  19. 2026-08-28 07:32 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-40541?
CVE-2026-40541 is a critical vulnerability published on August 28, 2026. An improper neutralization of input during web page generation ('Cross-site Scripting') vulnerability in extract domain in Synology Chat Server before 2.4.5-22148 allows remote authenticated users, via a UI interaction, to read or write arbitrary files and conduct denial-of-service attacks in DSM.
When was CVE-2026-40541 disclosed?
CVE-2026-40541 was first published in the National Vulnerability Database on August 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-40541 actively exploited?
CVE-2026-40541 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 60.6% of all scored CVEs.
What is the CVSS score of CVE-2026-40541?
CVE-2026-40541 has a CVSS v3 base score of 9.0 (NVD).
How do I remediate CVE-2026-40541?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-40541, 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

Explore the affected products and dependency analysis for CVE-2026-40541

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