CVE-2026-46621

CRITICALPre-NVD 9.19.1
EchelonGraph scoreMEDIUM confidence

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

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-05-27. A secondary CVSS source baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Elevated

Also known asEUVD-2026-44959 (ENISA EUVD) · GHSA-2g95-6x5q-xjwj (GitHub Security Advisories)Source: ENISA EUVD

9.1EG
EchelonGraph verdictPlan a fixRemediate 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: 1.1%CVSS: 9.1Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

Yamcs is a mission control framework. Prior to 5.12.7, the Yamcs script evaluation engine for Python algorithms dynamically compiled and evaluated user-controlled algorithm text using Jython through the JSR-223 ScriptEngine API without enforcing a secure sandbox, so an authenticated user with the ChangeMissionDatabase privilege could override an existing Python algorithm's logic through the mission database REST API and import and execute arbitrary Java classes such as java.lang.Runtime to achieve remote code execution on the underlying host operating system. This issue is fixed in versions 5.12.7 and 5.13.0, which disable algorithm editing by default.

CVSS v3
9.1
EG Score
9.1CRITICALmedium confidence
EG Risk
57
EG Risk 57/100

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)
Severity91% × 45%
Impact severity (EG Severity): CVSS 9.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
1.1%
EPSS %ILE
66th
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 (9.1): severity, escalated by confirmed exploitation. This CVE's 9.1 is its impact severity (EG Severity), not escalated.

EG Severity
9.1 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
1.1% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-13). 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 low, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 14 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 low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

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

May 27, 2026

Last Modified

July 20, 2026

Advisory Details (5)

Auto-updated Sep 16, 2026
Patch available. Sources: github_commit, github_release, github.
GitHub advisoryMentions a patch (unverified)

Authenticated Remote Code Execution (RCE) via Jython Algorithm Code Injection · Advisory · yamcs/yamcs · GitHub

https://github.com/yamcs/yamcs/security/advisories/GHSA-2g95-6x5q-xjwj
GitHub release Patch Available

Yamcs 5.13.0

Patch available: yamcs/yamcs yamcs-5.13.0

https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.0
GitHub release Patch Available

Yamcs 5.12.7

Patch available: yamcs/yamcs yamcs-5.12.7

https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.7
GitHub commit

commit 4ff8fda642ea (yamcs/yamcs)

Fix landed in yamcs/yamcs commit 4ff8fda642ea — awaiting tagged release

https://github.com/yamcs/yamcs/commit/4ff8fda642ea8c3309a4d3f379aa77b763148992
GitHub commit

commit 3c550348f866 (yamcs/yamcs)

Fix landed in yamcs/yamcs commit 3c550348f866 — awaiting tagged release

https://github.com/yamcs/yamcs/commit/3c550348f866af4675d2ba4a51d8d12b7c7c6011

Vendor Advisories for CVE-2026-46621(1)

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

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
mavenorg.yamcs:yamcs-core @ 5.12.7 (fixes < 5.12.7)—ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
Maven(1)
PackageVulnerable rangeFix by version rangeDependents
org.yamcs:yamcs-core0.29.3 ... 5.9.9 (165 versions)
  • every version up to 5.12.7: fixed in 5.12.7
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 43× 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.

Showing the most recent 100 of 188 rows 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. None are among the latest 100 rows. The 88 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 18:15 UTCEchelonGraph re-scored
  2. 2026-11-13 18:15 UTCGHSA enrichmentGHSA-2g95-6x5q-xjwj · GitHub severity CRITICAL · GitHub CVSS 9.1
  3. 2026-11-13 16:52 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  4. 2026-11-12 16:34 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  5. 2026-11-12 15:46 UTCEchelonGraph re-scored
  6. 2026-11-12 15:46 UTCGHSA enrichmentGHSA-2g95-6x5q-xjwj · GitHub severity CRITICAL · GitHub CVSS 9.1
  7. 2026-11-11 16:39 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  8. 2026-11-11 14:02 UTCEchelonGraph re-scored
  9. 2026-11-11 14:02 UTCGHSA enrichmentGHSA-2g95-6x5q-xjwj · GitHub severity CRITICAL · GitHub CVSS 9.1
  10. 2026-11-10 16:44 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  11. 2026-11-10 12:18 UTCEchelonGraph re-scored
  12. 2026-11-10 12:18 UTCGHSA enrichmentGHSA-2g95-6x5q-xjwj · GitHub severity CRITICAL · GitHub CVSS 9.1
  13. 2026-11-09 16:35 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  14. 2026-11-09 10:35 UTCEchelonGraph re-scored
  15. 2026-11-09 10:35 UTCGHSA enrichmentGHSA-2g95-6x5q-xjwj · GitHub severity CRITICAL · GitHub CVSS 9.1
  16. 2026-11-08 16:39 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  17. 2026-11-08 08:51 UTCEchelonGraph re-scored
  18. 2026-11-08 08:51 UTCGHSA enrichmentGHSA-2g95-6x5q-xjwj · GitHub severity CRITICAL · GitHub CVSS 9.1
  19. 2026-11-07 16:39 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  20. 2026-11-07 07:07 UTCEchelonGraph re-scored
  21. 2026-11-07 07:07 UTCGHSA enrichmentGHSA-2g95-6x5q-xjwj · GitHub severity CRITICAL · GitHub CVSS 9.1
  22. 2026-11-06 16:38 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  23. 2026-11-06 09:55 UTCOSV refresh
  24. 2026-11-06 05:21 UTCEchelonGraph re-scored
  25. 2026-11-06 05:21 UTCGHSA enrichmentGHSA-2g95-6x5q-xjwj · GitHub severity CRITICAL · GitHub CVSS 9.1
Show 75 more
  1. 2026-11-05 16:37 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  2. 2026-11-05 03:38 UTCEchelonGraph re-scored
  3. 2026-11-05 03:38 UTCGHSA enrichmentGHSA-2g95-6x5q-xjwj · GitHub severity CRITICAL · GitHub CVSS 9.1
  4. 2026-11-04 16:35 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  5. 2026-11-04 01:55 UTCEchelonGraph re-scored
  6. 2026-11-04 01:55 UTCGHSA enrichmentGHSA-2g95-6x5q-xjwj · GitHub severity CRITICAL · GitHub CVSS 9.1
  7. 2026-11-03 16:48 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  8. 2026-11-03 00:12 UTCEchelonGraph re-scored
  9. 2026-11-03 00:12 UTCGHSA enrichmentGHSA-2g95-6x5q-xjwj · GitHub severity CRITICAL · GitHub CVSS 9.1
  10. 2026-11-02 16:45 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  11. 2026-11-01 22:25 UTCEchelonGraph re-scored
  12. 2026-11-01 22:25 UTCGHSA enrichmentGHSA-2g95-6x5q-xjwj · GitHub severity CRITICAL · GitHub CVSS 9.1
  13. 2026-11-01 07:48 UTCGHSA enrichmentGHSA-2g95-6x5q-xjwj · GitHub severity CRITICAL · GitHub CVSS 9.1
  14. 2026-11-01 07:48 UTCEchelonGraph re-scored
  15. 2026-10-31 20:42 UTCEchelonGraph re-scored
  16. 2026-10-31 16:32 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  17. 2026-10-30 18:59 UTCEchelonGraph re-scored
  18. 2026-10-30 16:34 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  19. 2026-10-29 17:16 UTCEchelonGraph re-scored
  20. 2026-10-29 16:33 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  21. 2026-10-28 16:32 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  22. 2026-10-28 15:32 UTCEchelonGraph re-scored
  23. 2026-10-27 16:32 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  24. 2026-10-27 13:48 UTCEchelonGraph re-scored
  25. 2026-10-26 16:31 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  26. 2026-10-26 11:32 UTCEchelonGraph re-scored
  27. 2026-10-25 16:33 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  28. 2026-10-25 14:25 UTCEchelonGraph re-scored
  29. 2026-10-25 09:50 UTCEchelonGraph re-scored
  30. 2026-10-24 16:33 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  31. 2026-10-24 08:07 UTCEchelonGraph re-scored
  32. 2026-10-23 16:31 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  33. 2026-10-23 06:23 UTCEchelonGraph re-scored
  34. 2026-10-22 16:34 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  35. 2026-10-22 04:39 UTCEchelonGraph re-scored
  36. 2026-10-21 16:33 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  37. 2026-10-21 02:54 UTCEchelonGraph re-scored
  38. 2026-10-20 16:33 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  39. 2026-10-20 01:07 UTCEchelonGraph re-scored
  40. 2026-10-19 16:32 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  41. 2026-10-18 23:23 UTCEchelonGraph re-scored
  42. 2026-10-18 16:32 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  43. 2026-10-18 03:36 UTCEchelonGraph re-scored
  44. 2026-10-17 21:39 UTCEchelonGraph re-scored
  45. 2026-10-17 16:34 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  46. 2026-10-16 19:54 UTCEchelonGraph re-scored
  47. 2026-10-16 16:42 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  48. 2026-10-15 17:17 UTCEchelonGraph re-scored
  49. 2026-10-15 16:32 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  50. 2026-10-14 16:33 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  51. 2026-10-14 11:17 UTCEchelonGraph re-scored
  52. 2026-10-13 16:34 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  53. 2026-10-13 09:31 UTCEchelonGraph re-scored
  54. 2026-10-12 16:34 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  55. 2026-10-12 16:02 UTCEchelonGraph re-scored
  56. 2026-10-11 19:45 UTCEchelonGraph re-scored
  57. 2026-10-11 17:00 UTCEchelonGraph re-scored
  58. 2026-10-11 14:25 UTCEchelonGraph re-scored
  59. 2026-10-11 13:48 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  60. 2026-10-10 20:00 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  61. 2026-10-09 20:07 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  62. 2026-10-08 17:12 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  63. 2026-10-07 23:48 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  64. 2026-10-06 15:18 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  65. 2026-10-05 17:43 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  66. 2026-10-04 23:22 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  67. 2026-10-03 16:48 UTCOSV refresh
  68. 2026-10-03 14:25 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  69. 2026-10-01 19:50 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  70. 2026-09-30 15:03 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  71. 2026-09-28 13:51 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  72. 2026-09-27 13:48 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  73. 2026-09-26 15:59 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  74. 2026-09-26 00:27 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  75. 2026-09-23 17:53 UTCEPSS rescoreEPSS 1.1% · 64th percentile

Frequently asked(5)

What is CVE-2026-46621?
CVE-2026-46621 is a critical-severity vulnerability; its CVE record was published on May 27, 2026. Yamcs is a mission control framework. Prior to 5.12.7, the Yamcs script evaluation engine for Python algorithms dynamically compiled and evaluated user-controlled algorithm text using Jython through the JSR-223 ScriptEngine API without enforcing a secure sandbox, so an authenticated user with the…
When was the CVE record for CVE-2026-46621 published?
The CVE record for CVE-2026-46621 was published on May 27, 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 July 20, 2026; the record at its source may have been updated since.
Is CVE-2026-46621 actively exploited?
CVE-2026-46621 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.1% probability of exploitation in the next 30 days (66th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-46621?
CVE-2026-46621 has a CVSS base score of 9.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-46621?
A fix for CVE-2026-46621 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-46621 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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