CVE-2026-81421

HIGHPre-NVD 7.37.3
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 7.3 from GitHub Security Advisory published 2026-08-27. A secondary CVSS source baseline 7.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 3 sources updated this weekElevated
7.3EG
EchelonGraph verdictPlan mitigationRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 7.3Exploit: No code on recordExposed services: Not assessed

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

A security flaw has been discovered in ddfourtwo sentry-selfhosted-mcp 0.4.0. The affected element is an unknown function of the component raw_sentry_api. The manipulation of the argument endpoint results in server-side request forgery. It is possible to launch the attack remotely. The exploit has been released to the public and may be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.

CVSS v3
7.3
EG Score
7.3HIGHmedium confidence
EG Risk
64
EG Risk 64/100

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 (value × EchelonGraph’s weight)
Severity73% × 45%
The EG Score, 7.3 of 10.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
EPSS PROB
0.5%
EPSS %ILE
40th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

August 26, 2026

Last Modified

August 28, 2026

Advisory Details (2)

Auto-updated Aug 27, 2026
No fix on record yet.
Web page

GitHub - ddfourtwo/sentry-selfhosted-mcp: An MCP server for self-hosted sentry. · GitHub

https://github.com/ddfourtwo/sentry-selfhosted-mcp/
Web page

Server-Side Request Forgery Vulnerability in sentry-selfhosted-mcp · Issue #2 · ddfourtwo/sentry-selfhosted-mcp · GitHub

https://github.com/ddfourtwo/sentry-selfhosted-mcp/issues/2

Vendor Advisories for CVE-2026-81421(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 19× in last 7d / 98× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 99 of 170 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 100 is merged into the row it repeats. The 71 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  2. 2026-10-13 06:20 UTCEG score recompute
  3. 2026-10-13 06:20 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  4. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  5. 2026-10-12 14:56 UTCEG score recompute
  6. 2026-10-11 19:20 UTCEG score recompute
  7. 2026-10-11 16:37 UTCEG score recompute
  8. 2026-10-11 13:55 UTCEG score recompute
  9. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  10. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  11. 2026-10-10 06:01 UTCEG score recompute
  12. 2026-10-10 06:00 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  13. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  14. 2026-10-09 03:18 UTCEG score recompute
  15. 2026-10-09 03:18 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  16. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  17. 2026-10-08 01:29 UTCEG score recompute
  18. 2026-10-08 01:29 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  19. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  20. 2026-10-07 04:05 UTCEG score recompute
  21. 2026-10-07 04:05 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  22. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  23. 2026-10-06 14:59 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  24. 2026-10-06 01:40 UTCEG score recompute
  25. 2026-10-06 01:40 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
Show 74 more
  1. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  2. 2026-10-05 08:49 UTCEG score recompute
  3. 2026-10-05 08:49 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  4. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  5. 2026-10-04 19:41 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  6. 2026-10-04 05:10 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  7. 2026-10-03 16:05 UTCEG score recompute
  8. 2026-10-03 16:05 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  9. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  10. 2026-10-03 01:56 UTCEG score recompute
  11. 2026-10-03 01:56 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  12. 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  13. 2026-10-02 12:51 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  14. 2026-10-01 22:38 UTCEG score recompute
  15. 2026-10-01 22:38 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  16. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  17. 2026-10-01 09:04 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  18. 2026-09-30 19:57 UTCEG score recompute
  19. 2026-09-30 19:57 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  20. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  21. 2026-09-30 05:59 UTCEG score recompute
  22. 2026-09-30 05:59 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  23. 2026-09-29 14:32 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  24. 2026-09-29 01:24 UTCEG score recompute
  25. 2026-09-29 01:24 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  26. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  27. 2026-09-28 11:48 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  28. 2026-09-27 22:40 UTCEG score recompute
  29. 2026-09-27 22:40 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  30. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  31. 2026-09-27 09:35 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  32. 2026-09-26 20:29 UTCEG score recompute
  33. 2026-09-26 20:29 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  34. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  35. 2026-09-25 13:50 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  36. 2026-09-25 00:14 UTCEG score recompute
  37. 2026-09-25 00:14 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  38. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  39. 2026-09-24 10:50 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  40. 2026-09-23 21:43 UTCEG score recompute
  41. 2026-09-23 21:43 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  42. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  43. 2026-09-23 08:38 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  44. 2026-09-22 19:32 UTCEG score recompute
  45. 2026-09-22 19:32 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  46. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  47. 2026-09-22 06:27 UTCEG score recompute
  48. 2026-09-22 06:26 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  49. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  50. 2026-09-21 17:21 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  51. 2026-09-21 03:54 UTCEG score recompute
  52. 2026-09-21 03:54 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  53. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  54. 2026-09-20 14:47 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  55. 2026-09-20 01:41 UTCEG score recompute
  56. 2026-09-20 01:41 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  57. 2026-09-19 12:36 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  58. 2026-09-18 23:30 UTCEG score recompute
  59. 2026-09-18 23:30 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  60. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  61. 2026-09-18 10:24 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  62. 2026-09-17 21:18 UTCEG score recompute
  63. 2026-09-17 21:18 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  64. 2026-09-17 08:13 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  65. 2026-09-16 19:05 UTCEG score recompute
  66. 2026-09-16 19:05 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  67. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  68. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  69. 2026-09-16 03:24 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  70. 2026-09-15 14:15 UTCEG score recompute
  71. 2026-09-15 14:15 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  72. 2026-09-15 03:12 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  73. 2026-09-15 01:09 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3
  74. 2026-09-14 12:04 UTCGHSA enrichmentGHSA-77f3-qj56-x322 · GitHub CVSS 7.3

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-81421?
CVE-2026-81421 is a high-severity vulnerability; its CVE record was published on August 26, 2026. A security flaw has been discovered in ddfourtwo sentry-selfhosted-mcp 0.4.0. The affected element is an unknown function of the component rawsentryapi. The manipulation of the argument endpoint results in server-side request forgery. It is possible to launch the attack remotely. The exploit has…
When was the CVE record for CVE-2026-81421 published?
The CVE record for CVE-2026-81421 was published on August 26, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of August 28, 2026; the record at its source may have been updated since.
Is CVE-2026-81421 actively exploited?
CVE-2026-81421 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (40th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-81421?
CVE-2026-81421 has a CVSS base score of 7.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-81421?
No fix for CVE-2026-81421 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-81421 are linked in the Vendor Advisories panel on this page.

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