CVE-2026-66071

MEDIUMNVD 6.56.5
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 6.5 under NVD CVSS v3. EPSS exploit probability: 0.5% (46th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3

Also known asEUVD-2026-87151 (ENISA EUVD)Source: ENISA EUVD

6.5EG
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: 0.5%CVSS: 6.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.15 and 4.0.22 and 4.1.11 and 4.2.6 and 4.3.1, Atom exhaustion: OAuth2 JWT tag: scope values. extractscopes/1 parses scopes of the form .tag: and calls rabbitdatacoercion:toatom() to convert to a tag atom. The token signature is verified first, so the attacker cannot forge scopes , but in IdP configurations where scope content is user-influenced, each login with a novel tag value leaks one In deployments where users can influence the scopes included in their IdP-issued JWT rabbitmqauthbackendoauth2 enabled IdP permits attacker-influenced scope values in signed tokens. This issue is fixed in versions 3.13.15 and 4.0.22 and 4.1.11 and 4.2.6 and 4.3.1.

CVSS v3
6.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
29
EG Risk 29/100

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)
Severity65% × 45%
Impact severity (EG Severity): CVSS 6.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.5% × 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: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.5%
EPSS %ILE
46th
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 (6.5): severity, escalated by confirmed exploitation. This CVE's 6.5 is its impact severity (EG Severity), not escalated.

EG Severity
6.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS. 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.

A fix is available. 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 25, 2026

Last Modified

October 15, 2026

Advisory Details (5)

Auto-updated Sep 25, 2026
Patch available. Sources: github, github_commit, github_release.
GitHub release Patch Available

RabbitMQ 4.3.1

Patch available: rabbitmq/rabbitmq-server v4.3.1

https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1
GitHub release Patch Available

RabbitMQ 4.2.6

Patch available: rabbitmq/rabbitmq-server v4.2.6

https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6
GitHub commit

commit c5690583a537 (rabbitmq/rabbitmq-server)

Fix landed in rabbitmq/rabbitmq-server commit c5690583a537 — awaiting tagged release

https://github.com/rabbitmq/rabbitmq-server/commit/c5690583a53789a3bf00cca508b43e8246db0d11
GitHub commit

commit 9a44124d9c93 (rabbitmq/rabbitmq-server)

Fix landed in rabbitmq/rabbitmq-server commit 9a44124d9c93 — awaiting tagged release

https://github.com/rabbitmq/rabbitmq-server/commit/9a44124d9c932d6fc7d2a3b945e5a143e547bcb6
GitHub advisoryMentions a patch (unverified)

Atom exhaustion: OAuth2 JWT tag: scope values · Advisory · rabbitmq/rabbitmq-server · GitHub

https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-89p2-f5cv-x5cg

Vendor Advisories for CVE-2026-66071(2)

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
redhatrabbitmq-server4-3-main-4.3.6-1.hum12026-09-15redhat

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

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
rabbitmq-server3.10.8-1.1 ... 4.3.6-1 (29 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
rabbitmq-server4.0.5-10 ... 4.3.6-1 (19 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
rabbitmq-server4.0.5-10 ... 4.3.0-3 (11 versions)
  • every version up to 4.3.2-1: fixed in 4.3.2-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 34× 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.

  1. 2026-11-12 16:34 UTCEPSS rescoreEPSS 0.5% · 46th percentile
  2. 2026-11-11 16:40 UTCEPSS rescoreEPSS 0.5% · 46th percentile
  3. 2026-11-10 16:45 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  4. 2026-11-09 16:36 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  5. 2026-11-08 16:40 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  6. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  7. 2026-11-06 16:39 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  8. 2026-11-05 16:38 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  9. 2026-11-04 16:36 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  10. 2026-11-03 16:48 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  11. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  12. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  13. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  14. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  15. 2026-10-30 07:55 UTCOSV refresh
  16. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  17. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  18. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  19. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  20. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  21. 2026-10-25 14:11 UTCEchelonGraph re-scored
  22. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  23. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  24. 2026-10-22 19:37 UTCEchelonGraph re-scored
  25. 2026-10-22 19:37 UTCVendor advisory
Show 65 more
  1. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  2. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  3. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  4. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  5. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  6. 2026-10-18 03:21 UTCEchelonGraph re-scored
  7. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  8. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  9. 2026-10-15 20:29 UTCEchelonGraph re-scored▲ 0.50
  10. 2026-10-15 20:29 UTCVendor advisory
  11. 2026-10-15 20:28 UTCNVD updateCVSS v3 → 6.5
  12. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  13. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  14. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  15. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  16. 2026-10-12 15:46 UTCEchelonGraph re-scored
  17. 2026-10-12 01:40 UTCVendor advisory
  18. 2026-10-11 19:31 UTCEchelonGraph re-scored
  19. 2026-10-11 16:46 UTCEchelonGraph re-scored
  20. 2026-10-11 14:07 UTCEchelonGraph re-scored
  21. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  22. 2026-10-11 02:37 UTCEchelonGraph re-scored
  23. 2026-10-11 02:37 UTCVendor advisory
  24. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  25. 2026-10-10 03:15 UTCEchelonGraph re-scored
  26. 2026-10-10 03:15 UTCVendor advisory
  27. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  28. 2026-10-09 04:12 UTCEchelonGraph re-scored
  29. 2026-10-09 04:12 UTCVendor advisory
  30. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  31. 2026-10-08 05:09 UTCEchelonGraph re-scored
  32. 2026-10-08 05:09 UTCVendor advisory
  33. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  34. 2026-10-07 06:07 UTCEchelonGraph re-scored
  35. 2026-10-07 06:07 UTCVendor advisory
  36. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  37. 2026-10-06 07:05 UTCEchelonGraph re-scored
  38. 2026-10-06 07:05 UTCVendor advisory
  39. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  40. 2026-10-05 08:03 UTCEchelonGraph re-scored
  41. 2026-10-05 08:03 UTCVendor advisory
  42. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  43. 2026-10-04 09:01 UTCEchelonGraph re-scored
  44. 2026-10-04 09:01 UTCVendor advisory
  45. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  46. 2026-10-03 09:58 UTCEchelonGraph re-scored
  47. 2026-10-03 09:58 UTCVendor advisory
  48. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  49. 2026-10-02 10:53 UTCEchelonGraph re-scored
  50. 2026-10-02 10:53 UTCVendor advisory
  51. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  52. 2026-10-01 11:51 UTCEchelonGraph re-scored
  53. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  54. 2026-09-30 12:49 UTCEchelonGraph re-scored
  55. 2026-09-29 13:46 UTCEchelonGraph re-scored
  56. 2026-09-28 14:44 UTCEchelonGraph re-scored
  57. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  58. 2026-09-27 16:45 UTCEchelonGraph re-scored
  59. 2026-09-26 17:44 UTCEchelonGraph re-scored
  60. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  61. 2026-09-25 18:40 UTCEchelonGraph re-scored
  62. 2026-09-25 18:03 UTCEchelonGraph re-scored
  63. 2026-09-25 17:37 UTCEchelonGraph re-scored
  64. 2026-09-25 16:24 UTCEchelonGraph re-scoredFirst assessed: 6.0 MEDIUM
  65. 2026-09-25 16:24 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-66071?
CVE-2026-66071 is a medium-severity vulnerability; its CVE record was published on September 25, 2026. RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.15 and 4.0.22 and 4.1.11 and 4.2.6 and 4.3.1, Atom exhaustion: OAuth2 JWT tag: scope values. extractscopes/1 parses scopes of the form .tag: and calls rabbitdatacoercion:toatom() to convert to a tag atom. The token signature is…
When was the CVE record for CVE-2026-66071 published?
The CVE record for CVE-2026-66071 was published on September 25, 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 October 15, 2026; the record at its source may have been updated since.
Is CVE-2026-66071 actively exploited?
CVE-2026-66071 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (46th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-66071?
CVE-2026-66071 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-66071?
A fix for CVE-2026-66071 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-66071 are linked in the Vendor Advisories panel on this page.

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