A cross-site scripting vulnerability exists in acmailer, which may allow an attacker to execute an arbitrary script.
CVE-2026-66358
MEDIUMPre-NVD 6.16.1—Trending — 4 sources updated this week
EchelonGraph scoreHIGH confidence
Score 6.1 from GitHub Security Advisory published 2026-08-19. a secondary CVSS source baseline 6.1; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
6.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.1Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.1
- EG Score
- 6.1(high)
- EG Risk
- 28(Track)EG Risk 28/100SSVC: 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 computedSeverity61% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 7%
- KEV
- Not listed
Published
August 19, 2026
Last Modified
August 20, 2026
Advisory Details (2)
Auto-updated Aug 19, 2026No patch confirmed yet.
Vendor Advisories for CVE-2026-66358(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 11× in last 7d / 11× 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.
- 2026-08-20 22:56 UTCEPSS rescore
- 2026-08-20 16:38 UTCEG score recompute
- 2026-08-20 16:38 UTCGHSA enrichment
- 2026-08-20 15:46 UTCEG score recompute
- 2026-08-20 15:46 UTCGHSA enrichment
- 2026-08-20 05:19 UTCEG score recompute
- 2026-08-20 05:19 UTCGHSA enrichment
- 2026-08-19 17:04 UTCEPSS rescore
- 2026-08-19 05:19 UTCEG score recompute
- 2026-08-19 04:59 UTCEG score recompute
- 2026-08-19 04:57 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-66358?
CVE-2026-66358 is a medium vulnerability published on August 19, 2026. A cross-site scripting vulnerability exists in acmailer, which may allow an attacker to execute an arbitrary script.
When was CVE-2026-66358 disclosed?
CVE-2026-66358 was first published in the National Vulnerability Database on August 19, 2026, with the most recent update on August 20, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-66358 actively exploited?
CVE-2026-66358 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 93.4% of all scored CVEs.
What is the CVSS score of CVE-2026-66358?
CVE-2026-66358 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2026-66358?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66358, 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-2026-66358
Is Your Infrastructure Affected by CVE-2026-66358?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.