CVE-2026-66077

MEDIUMNVD 6.16.1
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 6.1 under NVD CVSS v3. EPSS exploit probability: 0.2% (4th 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
Trending — 4 sources updated this week

Also known asEUVD-2026-85628 (ENISA EUVD)Source: ENISA EUVD

6.1EG
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: 0.2%CVSS: 6.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, and 4.2.6, The management UI uses EJS 1.0 in which <%= ... %> does NOT HTML-escape. connection.ejs:135 renders <%= connection.ssl_details.peer_cert_subject %> (and peer_cert_issuer) directly into the page. The same pattern appears in streamConnection.ejs:102,106,110. The values come from rabbit_ssl:peer_cert_subject/1 which formats the DN as a string without HTML escaping. The verifier corrected the original researcher's claim: this is reachable only when the listener is configured with verify_peer (so the certificate must be signed by a CA in the broker's trust store, not arbitrary self-signed); however, in deployments using mTLS for client authentication, any user who can request a certificate from the organisational CA controls the Subject CN. An attacker who can obtain a TLS client certificate signed by a CA the broker trusts (with verify_peer enabled) can embed JavaScript in the certificate's Subject DN. When any administrator views that connection in the management UI, the script executes in the admin's browser session, allowing full account takeover (create users, export definitions, etc.). The management UI's CSP includes 'unsafe-inline', so inline script execution is not blocked. Preconditions include TLS listener configured with ssl_options.verify = verify_peer Attacker can obtain a CA-signed client certificate with attacker-chosen Subject (e.g. self-service corporate PKI, or rabbitmq_trust_store plugin in use) Administrator views the connection detail page. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, and 4.2.6.

CVSS v3
6.1
EG Score
6.1MEDIUMmedium confidence
EG Risk
28
EG Risk 28/100

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)
Severity61% × 45%
Impact severity (EG Severity): CVSS 6.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.1% × 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
0.2%
EPSS %ILE
4th
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 (6.1): severity, escalated by confirmed exploitation. This CVE's 6.1 is its impact severity (EG Severity), not escalated.

EG Severity
6.1 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
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-28). 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 23, 2026

Last Modified

October 19, 2026

Advisory Details (2)

Auto-updated Sep 23, 2026
Patch available. Sources: github, github_release.
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 advisoryMentions a patch (unverified)

Stored XSS via TLS peer-certificate DN in management UI · Advisory · rabbitmq/rabbitmq-server · GitHub

https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-rjcf-35r5-xw38

Vendor Advisories for CVE-2026-66077(2)

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

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubunturabbitmq-server (3.5.7-1ubuntu0.16.04.4+esm3) @ xenial2026-10-29ubuntu
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 ... 4.3.2-5 (28 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
rabbitmq-server4.0.5-10 ... 4.3.2-5 (18 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
rabbitmq-server4.0.5-10 ... 4.3.0-1 (9 versions)
  • every version up to 4.3.0-2: fixed in 4.3.0-2
—

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 10× in last 7d / 69× 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 105 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 5 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  3. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  4. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  5. 2026-10-29 14:43 UTCEG score recompute
  6. 2026-10-29 14:43 UTCVendor advisory
  7. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  8. 2026-10-28 12:55 UTCOSV refresh
  9. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  10. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  11. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  12. 2026-10-25 14:11 UTCEG score recompute
  13. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  14. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  15. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  16. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  17. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  18. 2026-10-19 20:47 UTCEG score recompute▼ 1.20
  19. 2026-10-19 20:47 UTCVendor advisory
  20. 2026-10-19 20:45 UTCNVD updateCVSS v3 → 6.1 · severity → MEDIUM
  21. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  22. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  23. 2026-10-18 03:21 UTCEG score recompute
  24. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  25. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.3% · 20th percentile
Show 75 more
  1. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  2. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  3. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  4. 2026-10-13 10:59 UTCEG score recompute
  5. 2026-10-13 10:59 UTCVendor advisory
  6. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  7. 2026-10-12 15:46 UTCEG score recompute
  8. 2026-10-12 02:24 UTCVendor advisory
  9. 2026-10-11 19:31 UTCEG score recompute
  10. 2026-10-11 16:46 UTCEG score recompute
  11. 2026-10-11 14:04 UTCEG score recompute
  12. 2026-10-11 14:04 UTCVendor advisory
  13. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  14. 2026-10-11 01:42 UTCEG score recompute
  15. 2026-10-11 01:42 UTCVendor advisory
  16. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  17. 2026-10-10 13:21 UTCVendor advisory
  18. 2026-10-10 01:00 UTCEG score recompute
  19. 2026-10-10 01:00 UTCVendor advisory
  20. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  21. 2026-10-09 12:39 UTCVendor advisory
  22. 2026-10-08 22:35 UTCEG score recompute
  23. 2026-10-08 22:35 UTCVendor advisory
  24. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  25. 2026-10-08 10:15 UTCEG score recompute
  26. 2026-10-08 10:15 UTCVendor advisory
  27. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  28. 2026-10-07 21:53 UTCVendor advisory
  29. 2026-10-07 09:23 UTCVendor advisory
  30. 2026-10-06 21:02 UTCEG score recompute
  31. 2026-10-06 21:02 UTCVendor advisory
  32. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  33. 2026-10-06 08:41 UTCVendor advisory
  34. 2026-10-05 20:09 UTCEG score recompute
  35. 2026-10-05 20:09 UTCVendor advisory
  36. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  37. 2026-10-05 07:49 UTCEG score recompute
  38. 2026-10-05 07:49 UTCVendor advisory
  39. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  40. 2026-10-04 19:28 UTCVendor advisory
  41. 2026-10-04 07:07 UTCVendor advisory
  42. 2026-10-03 18:47 UTCEG score recompute
  43. 2026-10-03 18:47 UTCVendor advisory
  44. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  45. 2026-10-03 06:23 UTCVendor advisory
  46. 2026-10-02 18:02 UTCEG score recompute
  47. 2026-10-02 18:02 UTCVendor advisory
  48. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  49. 2026-10-02 05:42 UTCEG score recompute
  50. 2026-10-02 05:42 UTCVendor advisory
  51. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  52. 2026-10-01 17:21 UTCVendor advisory
  53. 2026-10-01 04:58 UTCVendor advisory
  54. 2026-09-30 16:38 UTCEG score recompute
  55. 2026-09-30 16:38 UTCVendor advisory
  56. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  57. 2026-09-30 04:14 UTCVendor advisory
  58. 2026-09-29 15:53 UTCEG score recompute
  59. 2026-09-29 15:53 UTCVendor advisory
  60. 2026-09-29 03:33 UTCEG score recompute
  61. 2026-09-29 03:33 UTCVendor advisory
  62. 2026-09-29 02:36 UTCEG score recompute
  63. 2026-09-29 02:36 UTCVendor advisory
  64. 2026-09-28 18:14 UTCEG score recompute
  65. 2026-09-28 18:14 UTCVendor advisory
  66. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  67. 2026-09-28 05:37 UTCVendor advisory
  68. 2026-09-27 17:16 UTCEG score recompute
  69. 2026-09-27 17:16 UTCVendor advisory
  70. 2026-09-27 04:56 UTCVendor advisory
  71. 2026-09-26 16:32 UTCEG score recompute
  72. 2026-09-26 16:32 UTCVendor advisory
  73. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  74. 2026-09-26 04:09 UTCEG score recompute
  75. 2026-09-26 04:09 UTCVendor advisory

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Frequently asked(5)

What is CVE-2026-66077?
CVE-2026-66077 is a medium-severity vulnerability; its CVE record was published on September 23, 2026. RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, and 4.2.6, The management UI uses EJS 1.0 in which <%= ... %> does NOT HTML-escape. connection.ejs:135 renders <%= connection.ssl_details.peer_cert_subject %> (and peer_cert_issuer) directly into the page. The…
When was the CVE record for CVE-2026-66077 published?
The CVE record for CVE-2026-66077 was published on September 23, 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 19, 2026; the record at its source may have been updated since.
Is CVE-2026-66077 actively exploited?
CVE-2026-66077 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (4th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-66077?
CVE-2026-66077 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2026-66077?
A fix for CVE-2026-66077 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-66077 are linked in the Vendor Advisories panel on this page.

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