CVE-2026-92289

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreHIGH confidence

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-09-25. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this weekElevated
9.1EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 9.1Exploit: Elevated riskExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

Lemonldap::NG::Portal versions from 2.23.0 before 2.23.4 for Perl allow a PKCE bypass for public Relying Parties in "PKCE or secret" mode because checkEndPointAuthenticationCredentials does not verify the client secret.

With oidcRPMetaDataOptionsRequirePKCE set to 2, the authorization endpoint issues a code even when the request carries no code_challenge, and token() admits the exchange as long as a challenge was stored or an authentication method was returned for the caller. checkEndPointAuthenticationCredentials() skips the secret comparison for a Relying Party marked public and still returns the method deduced from the request, so any Basic or form credential satisfies the secret branch. validatePKCEChallenge() then passes, because neither a challenge nor a verifier is present.

An attacker who intercepts an authorization code issued to a public Relying Party can exchange it for the user's access, ID and refresh tokens by replaying the client_id with an arbitrary secret, which is the attack PKCE prevents. Dynamic client registration creates every Relying Party in this mode.

CVSS v3
9.1
EG Score
9.1CRITICALhigh confidence
EG Risk
72
EG Risk 72/100CISA 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
Severity91% × 45%
Exploitation40% × 40%
Automatability100% × 15%
CISA SSVC: Track at low, Track* at medium and Attend at high mission impact.
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
EPSS PROB
0.4%
EPSS %ILE
31st
KEV
Not listed

CISA SSVCTrack at low, Track* at medium and Attend at high mission impact.

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (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 26, 2026

Advisory Details (2)

Auto-updated Sep 26, 2026
No patch confirmed yet.
generic

Version 2.23.4 · LemonLDAP NG / lemonldap-ng · GitLab

https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/releases/v2.23.4
generic

[Security:medium, CVE-2026-92288, CVE-2026-92289] OIDC: public clients are treated as authenticated with any client secret (#3719) · Issues · LemonLDAP NG / lemonldap-ng · GitLab

https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/work_items/3719

Vendor Advisories for CVE-2026-92289(1)

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

Affected Packages

(1 across 1 ecosystem)
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
lemonldap-ng2.21.2+ds-1, 2.21.2+ds-1+deb13u1, 2.21.2+ds-1+deb13u2, 2.21.2+ds-1+deb13u3
  • every version up to 2.21.2+ds-1+deb13u4: fixed in 2.21.2+ds-1+deb13u4
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 56× in last 7d / 83× 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. 2026-10-05 10:21 UTCGHSA enrichment
  2. 2026-10-05 06:32 UTCGHSA enrichment
  3. 2026-10-05 02:42 UTCEG score recompute
  4. 2026-10-05 02:42 UTCGHSA enrichment
  5. 2026-10-04 23:22 UTCEPSS rescore
  6. 2026-10-04 22:53 UTCGHSA enrichment
  7. 2026-10-04 19:03 UTCGHSA enrichment
  8. 2026-10-04 15:13 UTCGHSA enrichment
  9. 2026-10-04 11:18 UTCGHSA enrichment
  10. 2026-10-04 07:28 UTCGHSA enrichment
  11. 2026-10-04 03:38 UTCGHSA enrichment
  12. 2026-10-03 23:49 UTCGHSA enrichment
  13. 2026-10-03 19:58 UTCGHSA enrichment
  14. 2026-10-03 16:09 UTCEG score recompute
  15. 2026-10-03 16:08 UTCGHSA enrichment
  16. 2026-10-03 12:19 UTCGHSA enrichment
  17. 2026-10-03 08:29 UTCGHSA enrichment
  18. 2026-10-03 04:33 UTCGHSA enrichment
  19. 2026-10-03 00:44 UTCGHSA enrichment
  20. 2026-10-02 20:55 UTCEG score recompute
  21. 2026-10-02 20:55 UTCGHSA enrichment
  22. 2026-10-02 17:05 UTCGHSA enrichment
  23. 2026-10-02 13:16 UTCGHSA enrichment
  24. 2026-10-02 09:27 UTCGHSA enrichment
  25. 2026-10-02 05:37 UTCGHSA enrichment
Show 58 more
  1. 2026-10-02 01:47 UTCGHSA enrichment
  2. 2026-10-01 21:53 UTCEG score recompute
  3. 2026-10-01 21:52 UTCGHSA enrichment
  4. 2026-10-01 19:51 UTCEPSS rescore
  5. 2026-10-01 17:56 UTCGHSA enrichment
  6. 2026-10-01 14:04 UTCGHSA enrichment
  7. 2026-10-01 10:15 UTCGHSA enrichment
  8. 2026-10-01 06:26 UTCGHSA enrichment
  9. 2026-10-01 02:37 UTCGHSA enrichment
  10. 2026-09-30 22:48 UTCGHSA enrichment
  11. 2026-09-30 18:59 UTCGHSA enrichment
  12. 2026-09-30 15:10 UTCEG score recompute
  13. 2026-09-30 15:10 UTCGHSA enrichment
  14. 2026-09-30 15:04 UTCEPSS rescore
  15. 2026-09-30 11:20 UTCGHSA enrichment
  16. 2026-09-30 07:31 UTCGHSA enrichment
  17. 2026-09-30 03:42 UTCGHSA enrichment
  18. 2026-09-29 23:52 UTCGHSA enrichment
  19. 2026-09-29 16:46 UTCEG score recompute
  20. 2026-09-29 16:46 UTCGHSA enrichment
  21. 2026-09-29 12:39 UTCGHSA enrichment
  22. 2026-09-29 08:50 UTCGHSA enrichment
  23. 2026-09-29 05:00 UTCGHSA enrichment
  24. 2026-09-29 01:11 UTCEG score recompute
  25. 2026-09-29 01:11 UTCGHSA enrichment
  26. 2026-09-28 21:21 UTCGHSA enrichment
  27. 2026-09-28 17:32 UTCEG score recompute
  28. 2026-09-28 17:31 UTCGHSA enrichment
  29. 2026-09-28 13:52 UTCEPSS rescore
  30. 2026-09-28 13:52 UTCEPSS rescore
  31. 2026-09-28 13:39 UTCGHSA enrichment
  32. 2026-09-28 09:50 UTCGHSA enrichment
  33. 2026-09-28 06:01 UTCGHSA enrichment
  34. 2026-09-28 02:12 UTCGHSA enrichment
  35. 2026-09-27 22:23 UTCGHSA enrichment
  36. 2026-09-27 18:34 UTCGHSA enrichment
  37. 2026-09-27 14:45 UTCEG score recompute
  38. 2026-09-27 14:45 UTCGHSA enrichment
  39. 2026-09-27 13:49 UTCEPSS rescore
  40. 2026-09-27 10:55 UTCGHSA enrichment
  41. 2026-09-27 07:06 UTCGHSA enrichment
  42. 2026-09-27 03:17 UTCEG score recompute
  43. 2026-09-27 03:17 UTCGHSA enrichment
  44. 2026-09-26 23:27 UTCGHSA enrichment
  45. 2026-09-26 22:36 UTCEG score recompute▲ 9.10
  46. 2026-09-26 22:35 UTCGHSA enrichment
  47. 2026-09-26 22:34 UTCMITRE cvelistV5CVSS v3 → 9.1 · severity → CRITICAL
  48. 2026-09-26 15:59 UTCEPSS rescore
  49. 2026-09-25 16:27 UTCGHSA enrichment
  50. 2026-09-25 16:25 UTCNVD update
  51. 2026-09-25 15:44 UTCGHSA enrichment
  52. 2026-09-25 15:44 UTCMITRE cvelistV5
  53. 2026-09-25 13:39 UTCGHSA enrichment
  54. 2026-09-25 03:21 UTCNVD update
  55. 2026-09-25 02:22 UTCMITRE cvelistV5
  56. 2026-09-25 01:18 UTCNVD update
  57. 2026-09-25 00:54 UTCEG score recompute
  58. 2026-09-25 00:53 UTCMITRE cvelistV5first tracked

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-92289?
CVE-2026-92289 is a critical vulnerability published on September 25, 2026. Lemonldap::NG::Portal versions from 2.23.0 before 2.23.4 for Perl allow a PKCE bypass for public Relying Parties in "PKCE or secret" mode because checkEndPointAuthenticationCredentials does not verify the client secret. With oidcRPMetaDataOptionsRequirePKCE set to 2, the authorization endpoint…
When was CVE-2026-92289 disclosed?
CVE-2026-92289 was first published on September 25, 2026, with the most recent update on September 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-92289 actively exploited?
CVE-2026-92289 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (31st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-92289?
CVE-2026-92289 has a CVSS v3.1 base score of 9.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-92289?
No fix for CVE-2026-92289 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-92289 are linked in the Vendor Advisories panel on this page.

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