CVE-2026-87913

MEDIUMPre-NVD 5.95.9
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 5.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4% (38th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source

Also known asEUVD-2026-75571 (ENISA EUVD)Source: ENISA EUVD

5.9EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 5.9Exploit: None knownExposed services: Not assessed

The CVE record names the fixed release — apply it.

A missing S3 bucket ownership verification in the AWS Security Agent MCP server before 0.2.0 version might allow remote attackers to obtain the private source archive of a scanned workspace, including credentials and infrastructure state contained in that archive, via a pre-registered storage bucket whose name is derived from a publicly known account identifier.

To remediate this issue, users should upgrade to version 0.2.0. Users should also verify that the scan output bucket in their account is owned by their own account, because upgrading does not release a bucket name that a third party has already registered.

CVSS v3
5.9
EG Score
5.9MEDIUMmedium confidence
EG Risk
27
EG Risk 27/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity59% × 45%
Impact severity (EG Severity): CVSS 5.9 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (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: The CVE record names the fixed release. Apply it within your standard update timelines.
EPSS PROB
0.4%
EPSS %ILE
38th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (5.9): severity, escalated by confirmed exploitation. This CVE's 5.9 is its impact severity (EG Severity), not escalated.

EG Severity
5.9 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

The CVE record names the fixed release. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (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)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (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

September 10, 2026

Last Modified

September 10, 2026

Advisory Details (3)

Auto-updated Sep 10, 2026
Fix named in the CVE record. Sources: github.
GitHub advisoryMentions a patch (unverified)

Missing S3 bucket ownership verification in the AWS Security Agent MCP server · Advisory · awslabs/mcp · GitHub

https://github.com/awslabs/mcp/security/advisories/GHSA-3jxw-vj8m-8x77
Web page

CVE-2026-87912 and CVE-2026-87913: Missing S3 bucket ownership verification in the AWS Security Agent plugin for aws-agents-for-devsecops and MCP Server

https://aws.amazon.com/security/security-bulletins/2026-105-aws/

Vendor Advisories for CVE-2026-87913(1)

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

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 30× 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 its CVE.org record (CNA or CISA ADP). 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

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.

  1. 2026-11-13 16:58 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  2. 2026-11-12 16:35 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  3. 2026-11-11 16:41 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  4. 2026-11-10 16:45 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  5. 2026-11-09 16:36 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  6. 2026-11-08 16:41 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  7. 2026-11-07 16:40 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  8. 2026-11-06 16:39 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  9. 2026-11-05 16:39 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  10. 2026-11-04 16:37 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  11. 2026-11-03 16:49 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  12. 2026-11-02 16:46 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  13. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  14. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  15. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  16. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  17. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  18. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  19. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  20. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  21. 2026-10-25 13:53 UTCEchelonGraph re-scored
  22. 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  23. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  24. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  25. 2026-10-22 12:35 UTCEchelonGraph re-scored
Show 74 more
  1. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  2. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  3. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  4. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  5. 2026-10-18 03:03 UTCEchelonGraph re-scored
  6. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  7. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  8. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  9. 2026-10-14 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  10. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  11. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  12. 2026-10-12 14:49 UTCEchelonGraph re-scored
  13. 2026-10-11 19:16 UTCEchelonGraph re-scored
  14. 2026-10-11 16:33 UTCEchelonGraph re-scored
  15. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  16. 2026-10-11 13:49 UTCEchelonGraph re-scored
  17. 2026-10-11 07:05 UTCEchelonGraph re-scored
  18. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  19. 2026-10-10 00:23 UTCEchelonGraph re-scored
  20. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  21. 2026-10-08 23:47 UTCEchelonGraph re-scored
  22. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  23. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  24. 2026-10-07 12:56 UTCEchelonGraph re-scored
  25. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  26. 2026-10-06 12:10 UTCEchelonGraph re-scored
  27. 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  28. 2026-10-05 11:34 UTCEchelonGraph re-scored
  29. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  30. 2026-10-04 10:57 UTCEchelonGraph re-scored
  31. 2026-10-03 10:21 UTCEchelonGraph re-scored
  32. 2026-10-02 09:11 UTCEchelonGraph re-scored
  33. 2026-10-01 19:51 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  34. 2026-10-01 08:34 UTCEchelonGraph re-scored
  35. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  36. 2026-09-30 07:58 UTCEchelonGraph re-scored
  37. 2026-09-29 07:22 UTCEchelonGraph re-scored
  38. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  39. 2026-09-28 06:46 UTCEchelonGraph re-scored
  40. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  41. 2026-09-27 06:10 UTCEchelonGraph re-scored
  42. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  43. 2026-09-26 05:34 UTCEchelonGraph re-scored
  44. 2026-09-25 04:46 UTCEchelonGraph re-scored
  45. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  46. 2026-09-24 04:10 UTCEchelonGraph re-scored
  47. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  48. 2026-09-23 03:34 UTCEchelonGraph re-scored
  49. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  50. 2026-09-22 02:57 UTCEchelonGraph re-scored
  51. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  52. 2026-09-21 02:20 UTCEchelonGraph re-scored
  53. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  54. 2026-09-20 01:43 UTCEchelonGraph re-scored
  55. 2026-09-19 01:07 UTCEchelonGraph re-scored
  56. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  57. 2026-09-18 00:31 UTCEchelonGraph re-scored
  58. 2026-09-17 19:32 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  59. 2026-09-16 23:55 UTCEchelonGraph re-scored
  60. 2026-09-16 14:09 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  61. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  62. 2026-09-15 23:18 UTCEchelonGraph re-scored
  63. 2026-09-15 03:12 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  64. 2026-09-13 22:00 UTCEchelonGraph re-scored
  65. 2026-09-13 16:48 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  66. 2026-09-12 21:24 UTCEchelonGraph re-scored
  67. 2026-09-12 15:02 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  68. 2026-09-11 20:48 UTCEchelonGraph re-scored
  69. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 16th percentile
  70. 2026-09-10 17:20 UTCEchelonGraph re-scored
  71. 2026-09-10 16:35 UTCEchelonGraph re-scored
  72. 2026-09-10 16:20 UTCEchelonGraph re-scored
  73. 2026-09-10 15:45 UTCEchelonGraph re-scoredFirst assessed: 5.9 MEDIUM
  74. 2026-09-10 15:44 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-87913?
CVE-2026-87913 is a medium-severity vulnerability; its CVE record was published on September 10, 2026. A missing S3 bucket ownership verification in the AWS Security Agent MCP server before 0.2.0 version might allow remote attackers to obtain the private source archive of a scanned workspace, including credentials and infrastructure state contained in that archive, via a pre-registered storage…
When was the CVE record for CVE-2026-87913 published?
The CVE record for CVE-2026-87913 was published on September 10, 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 September 10, 2026; the record at its source may have been updated since.
Is CVE-2026-87913 actively exploited?
CVE-2026-87913 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (38th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-87913?
CVE-2026-87913 has a CVSS base score of 5.9 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-87913?
The CVE record for CVE-2026-87913 names the fix: "To remediate this issue, users should upgrade to version 0.2.0." The vendor advisories EchelonGraph has for CVE-2026-87913 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-87913

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