CVE-2026-33657

MEDIUMNVD 4.64.6
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 4.6 under NVD CVSS v3. EPSS exploit probability: 0.2% (7th 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
Elevated

Also known asEUVD-2026-22081 (ENISA EUVD)Source: ENISA EUVD

4.6EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 4.6Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

EspoCRM is an open source customer relationship management application. Versions 9.3.3 and below have a stored HTML injection vulnerability that allows any authenticated user with standard (non-administrative) privileges to inject arbitrary HTML into system-generated email notifications by crafting malicious content in the post field of stream activity notes. The vulnerability exists because server-side Handlebars templates render the post field using unescaped triple-brace syntax, the Markdown processor preserves inline HTML by default, and the rendering pipeline explicitly skips sanitization for fields present in additionalData, creating a path where attacker-controlled HTML is accepted, stored, and rendered directly into emails without any escaping. Since the emails are sent using the system's configured SMTP identity (such as an administrative sender address), the injected content appears fully trusted to recipients, enabling phishing attacks, user tracking via embedded resources like image beacons, and UI manipulation within email content. The @mention feature further increases the impact by allowing targeted delivery of malicious emails to specific users. This issue has been fixed in version 9.3.4.

CVSS v3
4.6
EG Score
4.6MEDIUMmedium confidence
EG Risk
37
EG Risk 37/100

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)
Severity46% × 45%
Impact severity (EG Severity): CVSS 4.6 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation public PoC (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
7th
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 (4.6): severity, escalated by confirmed exploitation. This CVE's 4.6 is its impact severity (EG Severity), not escalated.

EG Severity
4.6 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. 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; Track* at high (mission-essential systems).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: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation public PoC (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.

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

April 13, 2026

Last Modified

April 22, 2026

Advisory Details (2)

Auto-updated Aug 3, 2026
Patch available. Sources: github_release, github.
GitHub advisoryMentions a patch (unverified)

Stored HTML injection in email notifications about stream notes via Markdown allowing HTML markup · Advisory · espocrm/espocrm · GitHub

https://github.com/espocrm/espocrm/security/advisories/GHSA-8prm-r5j9-j574
GitHub release Patch Available

Release 9.3.4 (espocrm/espocrm)

Patch available: espocrm/espocrm 9.3.4

https://github.com/espocrm/espocrm/releases/tag/9.3.4

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 36× 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 97 of 207 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. 3 repeat rows among the latest 100 are merged into the row they repeat. The 110 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-33657?
CVE-2026-33657 is a medium-severity vulnerability; its CVE record was published on April 13, 2026. EspoCRM is an open source customer relationship management application. Versions 9.3.3 and below have a stored HTML injection vulnerability that allows any authenticated user with standard (non-administrative) privileges to inject arbitrary HTML into system-generated email notifications by crafting…
When was the CVE record for CVE-2026-33657 published?
The CVE record for CVE-2026-33657 was published on April 13, 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 April 22, 2026; the record at its source may have been updated since.
Is CVE-2026-33657 actively exploited?
CVE-2026-33657 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (7th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-33657?
CVE-2026-33657 has a CVSS v3 base score of 4.6 (NVD).
How do I remediate CVE-2026-33657?
A fix for CVE-2026-33657 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-33657

Explore →

Is Your Infrastructure Affected by CVE-2026-33657?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs