CVE-2023-27582

CRITICALNVD 9.19.1
EchelonGraph scoreMEDIUM confidence

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

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 1.0% (63rd 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
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).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1.0%CVSS: 9.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

maddy is a composable, all-in-one mail server. Starting with version 0.2.0 and prior to version 0.6.3, maddy allows a full authentication bypass if SASL authorization username is specified when using the PLAIN authentication mechanisms. Instead of validating the specified username, it is accepted as is after checking the credentials for the authentication username. maddy 0.6.3 includes the fix for the bug. There are no known workarounds.

CVSS v3
9.1
EG Score
9.1CRITICALmedium confidence
EG Risk
56
EG Risk 56/100

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.
Exploitation1.0% × 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 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
1.0%
EPSS %ILE
63rd
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.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
1.0% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-21). 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: 3 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source: 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 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)3 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (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

March 13, 2023

Last Modified

November 21, 2024

Advisory Details (4)

Auto-updated Jul 22, 2026
Patch available. Sources: github_commit, github_release, github.
GitHub advisoryMentions a patch (unverified)

Full authentication bypass if SASL authorization username is specified · Advisory · foxcpp/maddy · GitHub

https://github.com/foxcpp/maddy/security/advisories/GHSA-4g76-w3xw-2x6w
GitHub release Patch Available

maddy 0.6.3

Patch available: foxcpp/maddy v0.6.3

https://github.com/foxcpp/maddy/releases/tag/v0.6.3
GitHub commit

commit 9f58cb64b39c (foxcpp/maddy)

Fix landed in foxcpp/maddy commit 9f58cb64b39c — awaiting tagged release

https://github.com/foxcpp/maddy/commit/9f58cb64b39cdc01928ec463bdb198c4c2313a9c
GitHub commit

commit 55a91a37b712 (foxcpp/maddy)

Fix landed in foxcpp/maddy commit 55a91a37b712 — awaiting tagged release

https://github.com/foxcpp/maddy/commit/55a91a37b71210f34f98f4d327c30308fe24399a

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFix by version rangeDependents
github.com/foxcpp/maddy—
  • 0.2.0 up to 0.6.3: fixed in 0.6.3
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 13× in last 7d / 42× 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 94 of 205 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. 6 repeat rows among the latest 100 are merged into the row they repeat. The 111 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-22 16:31 UTCEPSS rescoreEPSS 1.0% · 63rd percentile
  2. 2026-10-22 16:13 UTCEG score recompute
  3. 2026-10-21 16:29 UTCEPSS rescoreEPSS 1.0% · 63rd percentile
  4. 2026-10-21 14:05 UTCEG score recompute
  5. 2026-10-20 16:29 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
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  20. 2026-10-12 17:20 UTCEG score recompute
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  22. 2026-10-11 21:56 UTCEG score recompute
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  1. 2026-10-08 17:06 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  2. 2026-10-07 23:45 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  3. 2026-10-06 15:15 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
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  8. 2026-10-01 19:47 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  9. 2026-09-30 16:20 UTCEG score recompute
  10. 2026-09-30 15:01 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  11. 2026-09-29 15:16 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  12. 2026-09-28 13:49 UTCEPSS rescoreEPSS 1.0% · 61st percentile
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  14. 2026-09-26 00:22 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  15. 2026-09-24 14:01 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  16. 2026-09-23 18:52 UTCOSV refresh
  17. 2026-09-23 13:45 UTCEPSS rescoreEPSS 1.0% · 61st percentile
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  29. 2026-09-04 13:58 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  30. 2026-09-04 13:29 UTCOSV refresh
  31. 2026-09-04 05:04 UTCEPSS rescoreEPSS 1.0% · 61st percentile
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  46. 2026-08-18 00:59 UTCOSV refresh
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  69. 2026-07-26 14:52 UTCEPSS rescoreEPSS 1.0% · 59th percentile

Frequently asked(5)

What is CVE-2023-27582?
CVE-2023-27582 is a critical-severity vulnerability; its CVE record was published on March 13, 2023. maddy is a composable, all-in-one mail server. Starting with version 0.2.0 and prior to version 0.6.3, maddy allows a full authentication bypass if SASL authorization username is specified when using the PLAIN authentication mechanisms. Instead of validating the specified username, it is accepted…
When was the CVE record for CVE-2023-27582 published?
The CVE record for CVE-2023-27582 was published on March 13, 2023. 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 November 21, 2024; the record at its source may have been updated since.
Is CVE-2023-27582 actively exploited?
CVE-2023-27582 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.0% probability of exploitation in the next 30 days (63rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2023-27582?
CVE-2023-27582 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2023-27582?
A fix for CVE-2023-27582 is available: update to the fixed version the vendor names in its advisory.

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