CVE-2026-111056

MEDIUMPre-NVD 6.96.9
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 6.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3% (21st percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source

Also known asEUVD-2026-104418 (ENISA EUVD)Source: ENISA EUVD

6.9EG
EchelonGraph verdictMonitorRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 6.9Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

FOSSBilling is an open source billing and client-management platform. From 0.1.0 until 0.8.7, the unauthenticated POST /api/guest/client/create endpoint reveals whether a submitted email belongs to a registered client because guest signup returns a distinct unredacted error when the submitted email already exists. The trigger is an unauthenticated request to POST /api/guest/client/create with a target email address. An attacker can compare the guest-signup response for a target email to determine whether the email belongs to an existing FOSSBilling client. Box\Mod\Client\Api\Guest::create returns the error after Client\Service::clientAlreadyExists finds a matching record, and the API response exposes that exception message without redaction. This issue is fixed in version 0.8.7.

CVSS v3
6.9
EG Score
6.9MEDIUMmedium confidence
EG Risk
46
EG Risk 46/100

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)
Severity69% × 45%
Impact severity (EG Severity): CVSS 6.9 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.3% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (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 at low or medium mission impact and sooner than that at high.
EPSS PROB
0.3%
EPSS %ILE
21st
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 (6.9): severity, escalated by confirmed exploitation. This CVE's 6.9 is its impact severity (EG Severity), not escalated.

EG Severity
6.9 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.3% 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 low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days 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 or medium mission impact; Attend at high (mission-essential systems).

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

Exploitation none (CISA Vulnrichment) · Automatable yes (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)14 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (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

October 19, 2026

Last Modified

October 22, 2026

Advisory Details (4)

Auto-updated Oct 19, 2026
Patch available. Sources: github_commit, github_pr, github_release, github.
GitHub advisoryMentions a patch (unverified)

Unauthenticated client account enumeration via guest signup endpoint · Advisory · FOSSBilling/FOSSBilling · GitHub

https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-x4mh-g4pc-wfc5
GitHub release Patch Available

0.8.7

Patch available: FOSSBilling/FOSSBilling 0.8.7

https://github.com/FOSSBilling/FOSSBilling/releases/tag/0.8.7
GitHub pull request Patch Available

Harden guest signup against email enumeration (0.8-next)

Patch available: FOSSBilling/FOSSBilling 0.8.7 (PR #4234 merged 2026-08-28)

https://github.com/FOSSBilling/FOSSBilling/pull/4234
GitHub commit Patch Available

commit 19f41ff0a458 (FOSSBilling/FOSSBilling)

Patch available: FOSSBilling/FOSSBilling 0.8.7 (contains commit 19f41ff0a458)

https://github.com/FOSSBilling/FOSSBilling/commit/19f41ff0a45874c7362b7732c8f68db84bc59c55

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 20× 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.

  1. 2026-11-01 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  2. 2026-10-31 16:31 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  3. 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  4. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  5. 2026-10-29 15:09 UTCEG score recompute
  6. 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  7. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  8. 2026-10-26 16:30 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  9. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  10. 2026-10-25 14:52 UTCEG score recompute
  11. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  12. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  13. 2026-10-22 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  14. 2026-10-22 04:26 UTCEG score recompute
  15. 2026-10-22 03:21 UTCEG score recompute
  16. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  17. 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  18. 2026-10-19 16:38 UTCEG score recompute
  19. 2026-10-19 16:14 UTCEG score recomputeFirst assessed: 6.9 MEDIUM
  20. 2026-10-19 16:12 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-111056?
CVE-2026-111056 is a medium-severity vulnerability; its CVE record was published on October 19, 2026. FOSSBilling is an open source billing and client-management platform. From 0.1.0 until 0.8.7, the unauthenticated POST /api/guest/client/create endpoint reveals whether a submitted email belongs to a registered client because guest signup returns a distinct unredacted error when the submitted email…
When was the CVE record for CVE-2026-111056 published?
The CVE record for CVE-2026-111056 was published on October 19, 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 22, 2026; the record at its source may have been updated since.
Is CVE-2026-111056 actively exploited?
CVE-2026-111056 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (21st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-111056?
CVE-2026-111056 has a CVSS base score of 6.9 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-111056?
A fix for CVE-2026-111056 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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