CVE-2026-26747

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-02-20. 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
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.1Exploit: None knownExposed: 0

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

A Host Header Poisoning vulnerability exists in Monica 4.1.2 due to improper handling of the HTTP Host header in app/Providers/AppServiceProvider.php, combined with the default misconfiguration where the "app.force_url" is not set and default is "false". The application generates absolute URLs (such as those used in password reset emails) using the user-supplied Host header. This allows remote attackers to poison the password reset link sent to a victim,

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
46(Track)
EG Risk 46/100SSVC: Track

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%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
33%
KEV
Not listed

Published

February 20, 2026

Last Modified

June 17, 2026

Advisory Details (2)

Auto-updated Sep 16, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic

GitHub - monicahq/monica: Personal CRM. Remember everything about your friends, family and business relationships. · GitHub

https://github.com/monicahq/monica
generic🟡 PoC Available

cve-research/CVE-2026-26747.md at main · hungnqdz/cve-research · GitHub

https://github.com/hungnqdz/cve-research/blob/main/CVE-2026-26747.md

Weakness Classification(1)

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

Data Freshness Timeline

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

Frequently asked(5)

What is CVE-2026-26747?
CVE-2026-26747 is a critical vulnerability published on February 20, 2026. A Host Header Poisoning vulnerability exists in Monica 4.1.2 due to improper handling of the HTTP Host header in app/Providers/AppServiceProvider.php, combined with the default misconfiguration where the "app.force_url" is not set and default is "false". The application generates absolute URLs…
When was CVE-2026-26747 disclosed?
CVE-2026-26747 was first published in the National Vulnerability Database on February 20, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-26747 actively exploited?
CVE-2026-26747 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 67.0% of all scored CVEs.
What is the CVSS score of CVE-2026-26747?
CVE-2026-26747 has a CVSS v3.1 base score of 9.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-26747?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-26747, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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