CVE-2026-75511

MEDIUMPre-NVD 5.35.3
EchelonGraph scoreLOW confidence

This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). 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: secondary
Trending — 3 sources updated this week
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0

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

Novu provides an API for sending notifications through multiple channels. Prior to 3.18.0, Novu accepts chat webhook URLs from subscriber credentials.webhookUrl, channel endpoint endpoint.url, event payload.webhookUrl, and event overrides.webhookUrl, then passes the selected endpoint.url through send-message-chat.usecase.ts to raw HTTP requests in the Slack, Discord, Mattermost, Microsoft Teams, Grafana On-Call, Ryver, Rocket.Chat, GetStream, and Zulip providers. An authenticated user can supply an internal or otherwise restricted destination because these paths do not apply normalizeOutboundHttpUrl, assertSafeOutboundUrl, or the DNS-pinned safeOutboundJsonRequest protection used by the generic webhook providers. The Novu worker can consequently issue attacker-directed POST requests to internal network services and cause interactions or actions supported by those services. This issue is fixed in version 3.18.0.

CVSS v3
5.3
EG Score
5.3(low)
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 computed
Severity53% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
39%
KEV
Not listed

Published

September 22, 2026

Last Modified

September 22, 2026

Advisory Details (4)

Auto-updated Sep 22, 2026
Patch available. Sources: github_commit, github_pr, github_release, github.
github Patch Available

Server-Side Request Forgery (SSRF) via Chat Provider Webhook URLs · Advisory · novuhq/novu · GitHub

https://github.com/novuhq/novu/security/advisories/GHSA-pg9q-8v57-hqph
github_release Patch Available

v3.18.0

Patch available: novuhq/novu v3.18.0

https://github.com/novuhq/novu/releases/tag/v3.18.0
github_pr Patch Available

fix(providers): Harden chat webhook outbound requests fixes NV-7973

Patch available: novuhq/novu @novu/[email protected] (PR #11455 merged 2026-06-07)

https://github.com/novuhq/novu/pull/11455
github_commit Patch Available

commit dabfd66457c0 (novuhq/novu)

Patch available: novuhq/novu @novu/[email protected] (contains commit dabfd66457c0)

https://github.com/novuhq/novu/commit/dabfd66457c0b98ad46a8186e69f74f570a990c2

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 4× in last 7d / 4× 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. 2026-09-23 17:54 UTCEPSS rescore
  2. 2026-09-22 16:19 UTCEG score recompute
  3. 2026-09-22 15:55 UTCEG score recompute
  4. 2026-09-22 15:54 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-75511?
CVE-2026-75511 is a medium vulnerability published on September 22, 2026. Novu provides an API for sending notifications through multiple channels. Prior to 3.18.0, Novu accepts chat webhook URLs from subscriber credentials.webhookUrl, channel endpoint endpoint.url, event payload.webhookUrl, and event overrides.webhookUrl, then passes the selected endpoint.url through…
When was CVE-2026-75511 disclosed?
CVE-2026-75511 was first published in the National Vulnerability Database on September 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-75511 actively exploited?
CVE-2026-75511 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 60.5% of all scored CVEs.
What is the CVSS score of CVE-2026-75511?
CVE-2026-75511 has a CVSS v3 base score of 5.3 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-75511?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-75511, 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

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