CVE-2026-76239

MEDIUMPre-NVD 6.36.3—
EchelonGraph scoreMEDIUM confidence

Score 6.3 from GitHub Security Advisory published 2026-08-19. a secondary CVSS source baseline 6.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
6.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.3Exploit: Elevated riskExposed: 0

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

Stigmem before 0.9.0a11 fails to validate the delivery_address parameter when creating webhook subscriptions, allowing authenticated users to specify internal loopback and private network destinations. Attackers can trigger matching fact-change events to cause the Stigmem server to issue server-side HTTP POST requests to internal services, enabling blind SSRF attacks against localhost and private network endpoints.

CVSS v3
6.3
EG Score
6.3(medium)
EG Risk
44(Track)
EG Risk 44/100SSVC: 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
Severity63% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
19%
KEV
Not listed

Published

August 19, 2026

Last Modified

August 21, 2026

Advisory Details (2)

Auto-updated Aug 19, 2026
🔬 Proof of concept available. Patch available. Sources: github.
generic

Stigmem before 0.9.0a11 SSRF via unvalidated webhook delivery_address | Advisories | VulnCheck

https://www.vulncheck.com/advisories/stigmem-before-0a11-ssrf-via-unvalidated-webhook-delivery-address
github Patch Available🟡 PoC Available

Blind SSRF via unvalidated webhook subscription delivery_address · Advisory · eidetic-labs/stigmem · GitHub

https://github.com/eidetic-labs/stigmem/security/advisories/GHSA-5p3m-vhh6-9236

Vendor Advisories for CVE-2026-76239(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
stigmem-node0.9.0a1 ... 0.9.0a9 (10 versions)0.9.0a11—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 19× in last 7d / 84× 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. 2026-09-19 10:17 UTCEG score recompute
  2. 2026-09-19 10:17 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 12:05 UTCEG score recompute
  5. 2026-09-18 12:05 UTCGHSA enrichment
  6. 2026-09-17 13:58 UTCGHSA enrichment
  7. 2026-09-16 15:51 UTCEG score recompute
  8. 2026-09-16 15:51 UTCGHSA enrichment
  9. 2026-09-16 14:08 UTCEPSS rescore
  10. 2026-09-16 05:15 UTCEPSS rescore
  11. 2026-09-15 17:26 UTCEG score recompute
  12. 2026-09-15 17:26 UTCGHSA enrichment
  13. 2026-09-15 03:12 UTCEPSS rescore
  14. 2026-09-14 19:18 UTCGHSA enrichment
  15. 2026-09-13 19:50 UTCEG score recompute
  16. 2026-09-13 19:50 UTCGHSA enrichment
  17. 2026-09-12 21:43 UTCEG score recompute
  18. 2026-09-12 21:43 UTCGHSA enrichment
  19. 2026-09-12 15:02 UTCEPSS rescore
  20. 2026-09-11 23:36 UTCEG score recompute
  21. 2026-09-11 23:36 UTCGHSA enrichment
  22. 2026-09-11 14:53 UTCEPSS rescore
  23. 2026-09-11 00:59 UTCEG score recompute
  24. 2026-09-11 00:59 UTCGHSA enrichment
  25. 2026-09-10 09:35 UTCEPSS rescore
Show 64 more
  1. 2026-09-10 02:53 UTCGHSA enrichment
  2. 2026-09-09 04:46 UTCEG score recompute
  3. 2026-09-09 04:46 UTCGHSA enrichment
  4. 2026-09-08 22:01 UTCEPSS rescore
  5. 2026-09-08 06:24 UTCEG score recompute
  6. 2026-09-08 06:24 UTCGHSA enrichment
  7. 2026-09-07 08:16 UTCEG score recompute
  8. 2026-09-07 08:16 UTCGHSA enrichment
  9. 2026-09-06 13:48 UTCEPSS rescore
  10. 2026-09-06 09:46 UTCEG score recompute
  11. 2026-09-06 09:46 UTCGHSA enrichment
  12. 2026-09-05 11:40 UTCEG score recompute
  13. 2026-09-05 11:40 UTCGHSA enrichment
  14. 2026-09-04 13:33 UTCEG score recompute
  15. 2026-09-04 13:33 UTCGHSA enrichment
  16. 2026-09-04 05:07 UTCEPSS rescore
  17. 2026-09-03 15:18 UTCGHSA enrichment
  18. 2026-09-02 17:08 UTCEG score recompute
  19. 2026-09-02 17:08 UTCGHSA enrichment
  20. 2026-09-02 14:12 UTCEPSS rescore
  21. 2026-09-01 18:59 UTCEG score recompute
  22. 2026-09-01 18:58 UTCGHSA enrichment
  23. 2026-09-01 13:54 UTCEPSS rescore
  24. 2026-09-01 04:40 UTCEPSS rescore
  25. 2026-09-01 04:40 UTCEPSS rescore
  26. 2026-08-31 20:52 UTCGHSA enrichment
  27. 2026-08-30 22:16 UTCEG score recompute
  28. 2026-08-30 22:16 UTCGHSA enrichment
  29. 2026-08-30 19:18 UTCEPSS rescore
  30. 2026-08-30 19:17 UTCEPSS rescore
  31. 2026-08-30 01:22 UTCEPSS rescore
  32. 2026-08-30 00:09 UTCGHSA enrichment
  33. 2026-08-29 02:03 UTCEG score recompute
  34. 2026-08-29 02:02 UTCGHSA enrichment
  35. 2026-08-28 21:42 UTCEPSS rescore
  36. 2026-08-27 23:06 UTCGHSA enrichment
  37. 2026-08-27 00:59 UTCEG score recompute
  38. 2026-08-27 00:59 UTCGHSA enrichment
  39. 2026-08-26 14:47 UTCEPSS rescore
  40. 2026-08-26 02:52 UTCEG score recompute
  41. 2026-08-26 02:52 UTCGHSA enrichment
  42. 2026-08-25 13:49 UTCEPSS rescore
  43. 2026-08-25 04:45 UTCEG score recompute
  44. 2026-08-25 04:45 UTCGHSA enrichment
  45. 2026-08-24 14:18 UTCEPSS rescore
  46. 2026-08-24 06:39 UTCGHSA enrichment
  47. 2026-08-23 08:32 UTCEG score recompute
  48. 2026-08-23 08:32 UTCGHSA enrichment
  49. 2026-08-23 00:19 UTCEPSS rescore
  50. 2026-08-22 10:26 UTCEG score recompute
  51. 2026-08-22 10:26 UTCGHSA enrichment
  52. 2026-08-21 23:49 UTCEPSS rescore
  53. 2026-08-21 12:19 UTCEG score recompute
  54. 2026-08-21 12:19 UTCGHSA enrichment
  55. 2026-08-21 11:30 UTCEG score recompute
  56. 2026-08-21 11:30 UTCGHSA enrichment
  57. 2026-08-20 22:56 UTCEPSS rescore
  58. 2026-08-20 14:00 UTCEG score recompute
  59. 2026-08-20 14:00 UTCGHSA enrichment
  60. 2026-08-19 15:24 UTCEG score recompute
  61. 2026-08-19 14:57 UTCEG score recompute
  62. 2026-08-19 14:26 UTCEG score recompute
  63. 2026-08-19 14:12 UTCEG score recompute
  64. 2026-08-19 14:12 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-76239?
CVE-2026-76239 is a medium vulnerability published on August 19, 2026. Stigmem before 0.9.0a11 fails to validate the delivery_address parameter when creating webhook subscriptions, allowing authenticated users to specify internal loopback and private network destinations. Attackers can trigger matching fact-change events to cause the Stigmem server to issue…
When was CVE-2026-76239 disclosed?
CVE-2026-76239 was first published in the National Vulnerability Database on August 19, 2026, with the most recent update on August 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-76239 actively exploited?
CVE-2026-76239 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 81.3% of all scored CVEs.
What is the CVSS score of CVE-2026-76239?
CVE-2026-76239 has a CVSS v3 base score of 6.3 (NVD).
How do I remediate CVE-2026-76239?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-76239, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-76239

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