CVE-2026-100858

MEDIUMPre-NVD 6.86.8—
EchelonGraph scoreHIGH confidence

Score 6.8 from GitHub Security Advisory (severity: HIGH) published 2026-09-27. A secondary CVSS source baseline 6.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
6.8EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 6.8Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

heym before 0.0.109 contains a server-side request forgery vulnerability in the Slack, Discord, and Crawler workflow nodes. These nodes issue HTTP requests to URLs taken from user-created credentials (webhook_url / flaresolverr_url) using an unguarded HTTP client, bypassing the SSRF egress guard that already protects the HTTP, WebSocket, and MCP nodes; the credential API validates only that the URL is non-empty. Any registered user can create a credential pointing at an internal address and execute a workflow, causing the backend to reach loopback, private, link-local, or cloud-metadata endpoints and return the full response body in the node output (non-blind SSRF).

CVSS v3
6.8
EG Score
6.8MEDIUMhigh confidence
EG Risk
47
EG Risk 47/100CISA 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
Severity68% × 45%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low, Track* at medium and Attend at high mission impact.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.3%
EPSS %ILE
17th
KEV
Not listed

CISA SSVCTrack at low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (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 27, 2026

Last Modified

September 30, 2026

Advisory Details (2)

Auto-updated Sep 27, 2026
🔬 Proof of concept available. Patch available. Sources: github.
generic

heym before 0.0.109 Server-Side Request Forgery via Workflow Nodes | Advisories | VulnCheck

https://www.vulncheck.com/advisories/heym-before-0.0.109-server-side-request-forgery-via-workflow-nodes
github Patch Available🟡 PoC Available

SSRF in Slack, Discord, and Crawler Workflow Nodes · Advisory · heymrun/heym · GitHub

https://github.com/heymrun/heym/security/advisories/GHSA-39j3-6x3x-8rcr

Vendor Advisories for CVE-2026-100858(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 23× in last 7d / 28× 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. 2026-10-05 09:25 UTCEG score recompute
  2. 2026-10-05 09:25 UTCGHSA enrichment
  3. 2026-10-04 23:21 UTCEPSS rescore
  4. 2026-10-04 10:51 UTCEG score recompute
  5. 2026-10-04 10:51 UTCGHSA enrichment
  6. 2026-10-03 14:25 UTCEPSS rescore
  7. 2026-10-03 12:18 UTCEG score recompute
  8. 2026-10-03 12:18 UTCGHSA enrichment
  9. 2026-10-02 13:44 UTCEG score recompute
  10. 2026-10-02 13:44 UTCGHSA enrichment
  11. 2026-10-01 19:49 UTCEPSS rescore
  12. 2026-10-01 15:00 UTCGHSA enrichment
  13. 2026-09-30 16:27 UTCEG score recompute
  14. 2026-09-30 16:27 UTCGHSA enrichment
  15. 2026-09-30 15:53 UTCEG score recompute
  16. 2026-09-30 15:53 UTCGHSA enrichment
  17. 2026-09-30 15:02 UTCEPSS rescore
  18. 2026-09-29 19:50 UTCEG score recompute
  19. 2026-09-29 19:50 UTCGHSA enrichment
  20. 2026-09-29 15:20 UTCEPSS rescore
  21. 2026-09-28 21:13 UTCEG score recompute
  22. 2026-09-28 21:13 UTCGHSA enrichment
  23. 2026-09-28 13:50 UTCEPSS rescore
  24. 2026-09-28 01:10 UTCEG score recompute
  25. 2026-09-28 01:10 UTCGHSA enrichment
Show 3 more
  1. 2026-09-27 02:36 UTCEG score recompute
  2. 2026-09-27 01:53 UTCEG score recompute
  3. 2026-09-27 01:49 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-100858?
CVE-2026-100858 is a medium vulnerability published on September 27, 2026. heym before 0.0.109 contains a server-side request forgery vulnerability in the Slack, Discord, and Crawler workflow nodes. These nodes issue HTTP requests to URLs taken from user-created credentials (webhookurl / flaresolverrurl) using an unguarded HTTP client, bypassing the SSRF egress guard that…
When was CVE-2026-100858 disclosed?
CVE-2026-100858 was first published on September 27, 2026, with the most recent update on September 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-100858 actively exploited?
CVE-2026-100858 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-2026-100858?
CVE-2026-100858 has a CVSS base score of 6.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-100858?
A fix for CVE-2026-100858 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-100858 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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