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
Trending — 3 sources updated this weekElevated

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 2026-11-01). 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 15× in last 7d / 58× 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 100 of 153 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. None are among the latest 100 rows. The 53 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 22:25 UTCEG score recompute
  2. 2026-11-01 22:25 UTCGHSA enrichmentGHSA-2g95-6x5q-xjwj · GitHub severity CRITICAL · GitHub CVSS 9.1
  3. 2026-11-01 07:48 UTCGHSA enrichmentGHSA-2g95-6x5q-xjwj · GitHub severity CRITICAL · GitHub CVSS 9.1
  4. 2026-11-01 07:48 UTCEG score recompute
  5. 2026-10-31 20:42 UTCEG score recompute
  6. 2026-10-31 16:32 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  7. 2026-10-30 18:59 UTCEG score recompute
  8. 2026-10-30 16:34 UTCEPSS rescoreEPSS 1.1% · 66th percentile
  9. 2026-10-29 17:16 UTCEG score recompute
  10. 2026-10-29 16:33 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  11. 2026-10-28 16:32 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  12. 2026-10-28 15:32 UTCEG score recompute
  13. 2026-10-27 16:32 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  14. 2026-10-27 13:48 UTCEG score recompute
  15. 2026-10-26 16:31 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  16. 2026-10-26 11:32 UTCEG score recompute
  17. 2026-10-25 16:33 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  18. 2026-10-25 14:25 UTCEG score recompute
  19. 2026-10-25 09:50 UTCEG score recompute
  20. 2026-10-24 16:33 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  21. 2026-10-24 08:07 UTCEG score recompute
  22. 2026-10-23 16:31 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  23. 2026-10-23 06:23 UTCEG score recompute
  24. 2026-10-22 16:34 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  25. 2026-10-22 04:39 UTCEG score recompute
Show 75 more
  1. 2026-10-21 16:33 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  2. 2026-10-21 02:54 UTCEG score recompute
  3. 2026-10-20 16:33 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  4. 2026-10-20 01:07 UTCEG score recompute
  5. 2026-10-19 16:32 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  6. 2026-10-18 23:23 UTCEG score recompute
  7. 2026-10-18 16:32 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  8. 2026-10-18 03:36 UTCEG score recompute
  9. 2026-10-17 21:39 UTCEG score recompute
  10. 2026-10-17 16:34 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  11. 2026-10-16 19:54 UTCEG score recompute
  12. 2026-10-16 16:42 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  13. 2026-10-15 17:17 UTCEG score recompute
  14. 2026-10-15 16:32 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  15. 2026-10-14 16:33 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  16. 2026-10-14 11:17 UTCEG score recompute
  17. 2026-10-13 16:34 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  18. 2026-10-13 09:31 UTCEG score recompute
  19. 2026-10-12 16:34 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  20. 2026-10-12 16:02 UTCEG score recompute
  21. 2026-10-11 19:45 UTCEG score recompute
  22. 2026-10-11 17:00 UTCEG score recompute
  23. 2026-10-11 14:25 UTCEG score recompute
  24. 2026-10-11 13:48 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  25. 2026-10-10 20:00 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  26. 2026-10-09 20:07 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  27. 2026-10-08 17:12 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  28. 2026-10-07 23:48 UTCEPSS rescoreEPSS 1.1% · 65th percentile
  29. 2026-10-06 15:18 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  30. 2026-10-05 17:43 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  31. 2026-10-04 23:22 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  32. 2026-10-03 16:48 UTCOSV refresh
  33. 2026-10-03 14:25 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  34. 2026-10-01 19:50 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  35. 2026-09-30 15:03 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  36. 2026-09-28 13:51 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  37. 2026-09-27 13:48 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  38. 2026-09-26 15:59 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  39. 2026-09-26 00:27 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  40. 2026-09-23 17:53 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  41. 2026-09-20 20:15 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  42. 2026-09-18 19:28 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  43. 2026-09-17 19:31 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  44. 2026-09-16 14:08 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  45. 2026-09-16 05:15 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  46. 2026-09-14 07:32 UTCEG score recompute
  47. 2026-09-13 16:47 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  48. 2026-09-13 03:09 UTCOSV refresh
  49. 2026-09-12 15:01 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  50. 2026-09-11 14:53 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  51. 2026-09-11 09:37 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  52. 2026-09-10 09:34 UTCEPSS rescoreEPSS 1.1% · 64th percentile
  53. 2026-09-08 22:00 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  54. 2026-09-07 16:01 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  55. 2026-09-06 13:47 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  56. 2026-09-04 05:06 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  57. 2026-09-02 14:12 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  58. 2026-09-01 13:54 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  59. 2026-08-30 19:17 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  60. 2026-08-30 01:22 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  61. 2026-08-28 21:41 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  62. 2026-08-27 14:25 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  63. 2026-08-26 14:46 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  64. 2026-08-25 13:49 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  65. 2026-08-25 05:08 UTCEG score recompute
  66. 2026-08-23 14:51 UTCEG score recompute
  67. 2026-08-23 00:19 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  68. 2026-08-22 00:19 UTCEG score recompute
  69. 2026-08-21 23:49 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  70. 2026-08-21 01:19 UTCEG score recompute
  71. 2026-08-20 22:55 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  72. 2026-08-20 11:11 UTCEG score recompute
  73. 2026-08-19 17:04 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  74. 2026-08-18 13:48 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  75. 2026-08-17 13:47 UTCEPSS rescoreEPSS 1.0% · 59th 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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