CVE-2026-103602

MEDIUMNVD 5.35.3
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 5.3 under NVD CVSS v3. EPSS exploit probability: 0.2% (14th 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
Trending — 4 sources updated this week

Also known asEUVD-2026-91232 (ENISA EUVD) · GHSA-mx2f-845p-2h26 (GitHub Security Advisories)Source: ENISA EUVD

5.3EG
EchelonGraph verdictMonitorThe upstream fix is not in a release yet: until the release ships, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule, then apply it (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 5.3Exploit: None knownExposed services: Not assessed

An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.

Improper certificate validation in PkixNameConstraintValidator in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who controls, or can obtain certificates from, a name-constrained intermediate CA to have certificates accepted during PKIX certification path validation for email addresses, DNS names or URI hosts that lie within excluded subtrees applying to that CA, via an rfc822Name, dNSName or uniformResourceIdentifier name whose host ends with a dot, because names and constraints were compared without first removing the RFC 1034 root-label trailing dot, so a fully qualified host name did not match an excluded subtree for the same host written without the dot.

CVSS v3
5.3
EG Score
5.3MEDIUMmedium confidence
EG Risk
24
EG Risk 24/100

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)
Severity53% × 45%
Impact severity (EG Severity): CVSS 5.3 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.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (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: An upstream fix is merged but not yet in a tagged release. Until the release ships, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule, then apply it.
EPSS PROB
0.2%
EPSS %ILE
14th
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 (5.3): severity, escalated by confirmed exploitation. This CVE's 5.3 is its impact severity (EG Severity), not escalated.

EG Severity
5.3 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 every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.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 every mission impact level.

An upstream fix is merged but not yet in a tagged release. Until the release ships, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule, then apply it.

Exploitation none (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.

No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.

The score's inputs: 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

October 2, 2026

Last Modified

October 28, 2026

Advisory Details (4)

Auto-updated Oct 2, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
GitHub commit

commit 75c3c5766028 (bcgit/bc-csharp)

Fix landed in bcgit/bc-csharp commit 75c3c5766028 — awaiting tagged release

https://github.com/bcgit/bc-csharp/commit/75c3c576602886180ed92a63c89419e3bd63b392
GitHub commit

commit be276e057775 (bcgit/bc-csharp)

Fix landed in bcgit/bc-csharp commit be276e057775 — awaiting tagged release

https://github.com/bcgit/bc-csharp/commit/be276e057775a6a674a62e9d9a2583b229978f73
GitHub commit

commit f196a22bbf77 (bcgit/bc-csharp)

Fix landed in bcgit/bc-csharp commit f196a22bbf77 — awaiting tagged release

https://github.com/bcgit/bc-csharp/commit/f196a22bbf7765cc19b0c4f4645c74ea7ad35e09
Web page

CVE 2026 103602 · bcgit/bc-csharp Wiki · GitHub

https://github.com/bcgit/bc-csharp/wiki/CVE-2026-103602

Vendor Advisories for CVE-2026-103602(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 76× 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.

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 88 are merged into the row they repeat.

  1. 2026-11-01 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  2. 2026-10-31 16:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  3. 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  4. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  5. 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  6. 2026-10-28 13:48 UTCEG score recompute▼ 2.90
  7. 2026-10-28 13:47 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  8. 2026-10-28 13:46 UTCNVD updateCVSS v3 → 5.3 · severity → MEDIUM
  9. 2026-10-27 20:36 UTCEG score recompute
  10. 2026-10-27 20:36 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  11. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  12. 2026-10-26 16:30 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  13. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  14. 2026-10-25 14:56 UTCEG score recompute
  15. 2026-10-24 16:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  16. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  17. 2026-10-22 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  18. 2026-10-21 16:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  19. 2026-10-20 19:15 UTCEG score recompute
  20. 2026-10-20 19:15 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  21. 2026-10-20 16:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  22. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  23. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  24. 2026-10-18 05:09 UTCEG score recompute
  25. 2026-10-17 19:43 UTCEG score recompute
Show 60 more
  1. 2026-10-17 19:43 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  2. 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  3. 2026-10-16 16:40 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  4. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  5. 2026-10-14 16:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  6. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  7. 2026-10-12 16:40 UTCEG score recompute
  8. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  9. 2026-10-12 01:14 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  10. 2026-10-11 20:15 UTCEG score recompute
  11. 2026-10-11 18:28 UTCEG score recompute
  12. 2026-10-11 15:01 UTCEG score recompute
  13. 2026-10-11 13:47 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  14. 2026-10-11 13:27 UTCEG score recompute
  15. 2026-10-11 13:27 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  16. 2026-10-11 01:51 UTCEG score recompute
  17. 2026-10-11 01:51 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  18. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  19. 2026-10-10 14:17 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  20. 2026-10-10 02:41 UTCEG score recompute
  21. 2026-10-10 02:40 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  22. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  23. 2026-10-09 15:08 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  24. 2026-10-09 03:04 UTCEG score recompute
  25. 2026-10-09 03:03 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  26. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  27. 2026-10-08 15:30 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  28. 2026-10-08 01:48 UTCEG score recompute
  29. 2026-10-08 01:48 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  30. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  31. 2026-10-07 14:15 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  32. 2026-10-07 02:32 UTCEG score recompute
  33. 2026-10-07 02:32 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  34. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  35. 2026-10-06 14:59 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  36. 2026-10-06 03:26 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  37. 2026-10-06 03:26 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  38. 2026-10-06 03:26 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  39. 2026-10-06 03:25 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  40. 2026-10-06 03:25 UTCEG score recompute
  41. 2026-10-06 03:25 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  42. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  43. 2026-10-05 15:50 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  44. 2026-10-05 04:04 UTCEG score recompute
  45. 2026-10-05 04:04 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  46. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  47. 2026-10-04 16:30 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  48. 2026-10-04 04:57 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  49. 2026-10-03 17:25 UTCEG score recompute
  50. 2026-10-03 17:25 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  51. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  52. 2026-10-03 05:53 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  53. 2026-10-02 18:20 UTCEG score recompute
  54. 2026-10-02 18:20 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  55. 2026-10-02 17:55 UTCEG score recompute
  56. 2026-10-02 17:55 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  57. 2026-10-02 14:45 UTCGHSA enrichmentGHSA-mx2f-845p-2h26 · GitHub severity HIGH
  58. 2026-10-02 08:27 UTCEG score recompute
  59. 2026-10-02 07:31 UTCEG score recomputeFirst assessed: 8.2 HIGH
  60. 2026-10-02 07:30 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-103602?
CVE-2026-103602 is a medium-severity vulnerability; its CVE record was published on October 2, 2026. Improper certificate validation in PkixNameConstraintValidator in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who controls, or can obtain certificates from, a name-constrained intermediate CA to have certificates accepted during PKIX certification path validation for…
When was the CVE record for CVE-2026-103602 published?
The CVE record for CVE-2026-103602 was published on October 2, 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 28, 2026; the record at its source may have been updated since.
Is CVE-2026-103602 actively exploited?
CVE-2026-103602 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (14th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-103602?
CVE-2026-103602 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-103602?
An upstream fix for CVE-2026-103602 has been merged but is not yet in a tagged release. Until it ships, restrict network exposure of the affected system or apply the vendor's mitigation, then update to the release that contains the fix. The vendor advisories EchelonGraph has for CVE-2026-103602 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-103602

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