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: 0.3%CVSS: 6.3Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

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
6.3MEDIUMmedium confidence
EG Risk
44
EG Risk 44/100CISA 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
Severity63% × 45%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.3%
EPSS %ILE
23rd
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (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

August 19, 2026

Last Modified

September 24, 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 rangeFix by version rangeDependents
stigmem-node0.9.0a1 ... 0.9.0a9 (10 versions)
  • every version up to 0.9.0a11: fixed in 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 / 79× 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.

Showing the most recent 100 of 132 total refreshes for this CVE.

  1. 2026-10-05 01:46 UTCEG score recompute
  2. 2026-10-05 01:46 UTCGHSA enrichment
  3. 2026-10-04 23:22 UTCEPSS rescore
  4. 2026-10-04 03:21 UTCEG score recompute
  5. 2026-10-04 03:21 UTCGHSA enrichment
  6. 2026-10-03 14:26 UTCEPSS rescore
  7. 2026-10-03 05:14 UTCEG score recompute
  8. 2026-10-03 05:14 UTCGHSA enrichment
  9. 2026-10-02 06:51 UTCEG score recompute
  10. 2026-10-02 06:51 UTCGHSA enrichment
  11. 2026-10-01 19:50 UTCEPSS rescore
  12. 2026-10-01 06:56 UTCEG score recompute
  13. 2026-10-01 06:56 UTCGHSA enrichment
  14. 2026-09-30 08:50 UTCEG score recompute
  15. 2026-09-30 08:50 UTCGHSA enrichment
  16. 2026-09-29 15:24 UTCEPSS rescore
  17. 2026-09-29 03:22 UTCEG score recompute
  18. 2026-09-29 03:22 UTCGHSA enrichment
  19. 2026-09-28 13:52 UTCEPSS rescore
  20. 2026-09-28 05:10 UTCEG score recompute
  21. 2026-09-28 05:10 UTCGHSA enrichment
  22. 2026-09-27 13:48 UTCEPSS rescore
  23. 2026-09-27 07:04 UTCEG score recompute
  24. 2026-09-27 07:04 UTCGHSA enrichment
  25. 2026-09-26 15:59 UTCEPSS rescore
Show 75 more
  1. 2026-09-26 00:28 UTCEPSS rescore
  2. 2026-09-24 20:15 UTCEG score recompute
  3. 2026-09-24 20:15 UTCGHSA enrichment
  4. 2026-09-24 14:04 UTCEPSS rescore
  5. 2026-09-24 02:17 UTCEG score recompute
  6. 2026-09-24 02:17 UTCGHSA enrichment
  7. 2026-09-23 17:54 UTCEPSS rescore
  8. 2026-09-23 04:11 UTCEG score recompute
  9. 2026-09-23 04:11 UTCGHSA enrichment
  10. 2026-09-22 16:01 UTCEPSS rescore
  11. 2026-09-22 06:05 UTCEG score recompute
  12. 2026-09-22 06:05 UTCGHSA enrichment
  13. 2026-09-21 21:09 UTCEPSS rescore
  14. 2026-09-21 07:55 UTCEG score recompute
  15. 2026-09-21 07:55 UTCGHSA enrichment
  16. 2026-09-20 20:16 UTCEPSS rescore
  17. 2026-09-20 09:10 UTCEG score recompute
  18. 2026-09-20 09:10 UTCGHSA enrichment
  19. 2026-09-19 10:17 UTCEG score recompute
  20. 2026-09-19 10:17 UTCGHSA enrichment
  21. 2026-09-18 19:28 UTCEPSS rescore
  22. 2026-09-18 12:05 UTCEG score recompute
  23. 2026-09-18 12:05 UTCGHSA enrichment
  24. 2026-09-17 13:58 UTCGHSA enrichment
  25. 2026-09-16 15:51 UTCEG score recompute
  26. 2026-09-16 15:51 UTCGHSA enrichment
  27. 2026-09-16 14:08 UTCEPSS rescore
  28. 2026-09-16 05:15 UTCEPSS rescore
  29. 2026-09-15 17:26 UTCEG score recompute
  30. 2026-09-15 17:26 UTCGHSA enrichment
  31. 2026-09-15 03:12 UTCEPSS rescore
  32. 2026-09-14 19:18 UTCGHSA enrichment
  33. 2026-09-13 19:50 UTCEG score recompute
  34. 2026-09-13 19:50 UTCGHSA enrichment
  35. 2026-09-12 21:43 UTCEG score recompute
  36. 2026-09-12 21:43 UTCGHSA enrichment
  37. 2026-09-12 15:02 UTCEPSS rescore
  38. 2026-09-11 23:36 UTCEG score recompute
  39. 2026-09-11 23:36 UTCGHSA enrichment
  40. 2026-09-11 14:53 UTCEPSS rescore
  41. 2026-09-11 00:59 UTCEG score recompute
  42. 2026-09-11 00:59 UTCGHSA enrichment
  43. 2026-09-10 09:35 UTCEPSS rescore
  44. 2026-09-10 02:53 UTCGHSA enrichment
  45. 2026-09-09 04:46 UTCEG score recompute
  46. 2026-09-09 04:46 UTCGHSA enrichment
  47. 2026-09-08 22:01 UTCEPSS rescore
  48. 2026-09-08 06:24 UTCEG score recompute
  49. 2026-09-08 06:24 UTCGHSA enrichment
  50. 2026-09-07 08:16 UTCEG score recompute
  51. 2026-09-07 08:16 UTCGHSA enrichment
  52. 2026-09-06 13:48 UTCEPSS rescore
  53. 2026-09-06 09:46 UTCEG score recompute
  54. 2026-09-06 09:46 UTCGHSA enrichment
  55. 2026-09-05 11:40 UTCEG score recompute
  56. 2026-09-05 11:40 UTCGHSA enrichment
  57. 2026-09-04 13:33 UTCEG score recompute
  58. 2026-09-04 13:33 UTCGHSA enrichment
  59. 2026-09-04 05:07 UTCEPSS rescore
  60. 2026-09-03 15:18 UTCGHSA enrichment
  61. 2026-09-02 17:08 UTCEG score recompute
  62. 2026-09-02 17:08 UTCGHSA enrichment
  63. 2026-09-02 14:12 UTCEPSS rescore
  64. 2026-09-01 18:59 UTCEG score recompute
  65. 2026-09-01 18:58 UTCGHSA enrichment
  66. 2026-09-01 13:54 UTCEPSS rescore
  67. 2026-09-01 04:40 UTCEPSS rescore
  68. 2026-09-01 04:40 UTCEPSS rescore
  69. 2026-08-31 20:52 UTCGHSA enrichment
  70. 2026-08-30 22:16 UTCEG score recompute
  71. 2026-08-30 22:16 UTCGHSA enrichment
  72. 2026-08-30 19:18 UTCEPSS rescore
  73. 2026-08-30 19:17 UTCEPSS rescore
  74. 2026-08-30 01:22 UTCEPSS rescore
  75. 2026-08-30 00:09 UTCGHSA enrichment

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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 on August 19, 2026, with the most recent update on September 24, 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 0.3% probability of exploitation in the next 30 days (23rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-76239?
CVE-2026-76239 has a CVSS base score of 6.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-76239?
A fix for CVE-2026-76239 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-76239 are linked in the Vendor Advisories panel on this page.

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