CVE-2026-66071

MEDIUMPre-NVD 6.06.0—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.0 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3% (25th percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 3 sources updated this week
6.0EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 6.0Exploit: 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
6.0
EG Score
6.0MEDIUMmedium confidence
EG Risk
27
EG Risk 27/100CISA SSVC

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
Severity60% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.3%
EPSS %ILE
25th
KEV
Not listed

CISA SSVCTrack 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). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 25, 2026

Last Modified

September 28, 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 Patch Available

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(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 / EcosystemFixed in / 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.

Weakness Classification(1)

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

Additional Vendor Advisories

(1)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 16× in last 7d / 23× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

  1. 2026-10-04 09:01 UTCEG score recompute
  2. 2026-10-04 09:01 UTCVendor advisory
  3. 2026-10-03 14:26 UTCEPSS rescore
  4. 2026-10-03 09:58 UTCEG score recompute
  5. 2026-10-03 09:58 UTCVendor advisory
  6. 2026-10-02 17:56 UTCEPSS rescore
  7. 2026-10-02 10:53 UTCEG score recompute
  8. 2026-10-02 10:53 UTCVendor advisory
  9. 2026-10-01 19:50 UTCEPSS rescore
  10. 2026-10-01 11:51 UTCEG score recompute
  11. 2026-09-30 15:03 UTCEPSS rescore
  12. 2026-09-30 12:49 UTCEG score recompute
  13. 2026-09-29 13:46 UTCEG score recompute
  14. 2026-09-28 14:44 UTCEG score recompute
  15. 2026-09-28 13:51 UTCEPSS rescore
  16. 2026-09-27 16:45 UTCEG score recompute
  17. 2026-09-26 17:44 UTCEG score recompute
  18. 2026-09-26 15:59 UTCEPSS rescore
  19. 2026-09-25 18:40 UTCEG score recompute
  20. 2026-09-25 18:03 UTCEG score recompute
  21. 2026-09-25 17:37 UTCEG score recompute
  22. 2026-09-25 16:24 UTCEG score recompute
  23. 2026-09-25 16:24 UTCMITRE cvelistV5first tracked

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-66071?
CVE-2026-66071 is a medium vulnerability 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 CVE-2026-66071 disclosed?
CVE-2026-66071 was first published on September 25, 2026, with the most recent update on September 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-66071 actively exploited?
CVE-2026-66071 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (25th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-66071?
CVE-2026-66071 has a CVSS base score of 6.0 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
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.

Dependency Blast Radius

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