CVE-2026-59638

HIGHNVD 6.58.6
EchelonGraph scoreMEDIUM confidence

“▲” beside the score: it is higher than NVD's CVSS score.

Score 8.6 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-03. NVD baseline CVSS 6.5; sources differ by 2.1.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3

Also known asEUVD-2026-52016 (ENISA EUVD) · GHSA-8rxj-3p7p-rq39 (GitHub Security Advisories)Source: ENISA EUVD

8.6EG
EchelonGraph verdictMonitorRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 6.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

In Bouncy Castle for Java before 1.85, JSSE hostname verifier CN-fallback enabled by default despite documented opt-in. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bctls-fips 1.0.24 (1.0.X series), 2.0.24 (2.0.X series) and 2.1.24 (2.1.X series).

CVSS v3
6.5
EG Score
8.6HIGHmedium confidence
EG Risk
54
EG Risk 54/100

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)
Severity86% × 45%
Impact severity (EG Severity): CVSS 8.6 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 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
0.3%
EPSS %ILE
28th
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 (8.6): severity, escalated by confirmed exploitation. This CVE's 8.6 is its impact severity (EG Severity), not escalated.

EG Severity
8.6 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-09). 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, and whom BOD 26-04 binds: 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.

The score's inputs: 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

August 3, 2026

Last Modified

August 28, 2026

Advisory Details (4)

Auto-updated Aug 23, 2026
Patch available. Sources: github_commit.
Web page

CVE‐2026‐59638 · bcgit/bc-java Wiki · GitHub

https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9059638
GitHub commit

commit 799bd15320a6 (bcgit/bc-java)

Fix landed in bcgit/bc-java commit 799bd15320a6 — awaiting tagged release

https://github.com/bcgit/bc-java/commit/799bd15320a6310a447863638aa3df64acef829b
GitHub commit

commit 5ac55351cd1a (bcgit/bc-java)

Fix landed in bcgit/bc-java commit 5ac55351cd1a — awaiting tagged release

https://github.com/bcgit/bc-java/commit/5ac55351cd1a8a7184d41c96a7ee87df0770240a
Web page

Home · bcgit/bc-java Wiki · GitHub

https://github.com/bcgit/bc-java/wiki/CVE-2026-59638

Vendor Advisories for CVE-2026-59638(1)

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

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
bouncycastle1.68-2 ... 1.80-3 (12 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
bouncycastle1.72-2 ... 1.86-1 (6 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
bouncycastle1.80-3, 1.86-1
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
bouncycastle1.80-3
  • every version up to 1.86-1: fixed in 1.86-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 34× 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 its CVE.org record (CNA or CISA ADP). 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 386 rows 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. None are among the latest 100 rows. The 286 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-12 16:34 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  2. 2026-11-11 16:40 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  3. 2026-11-10 16:44 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  4. 2026-11-10 15:06 UTCEchelonGraph re-scored
  5. 2026-11-10 15:06 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  6. 2026-11-09 16:35 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  7. 2026-11-08 16:40 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  8. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  9. 2026-11-06 16:38 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  10. 2026-11-05 16:38 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  11. 2026-11-04 16:36 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  12. 2026-11-03 18:57 UTCEchelonGraph re-scored
  13. 2026-11-03 18:57 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  14. 2026-11-03 16:48 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  15. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  16. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  17. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  18. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  19. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.3% · 28th percentile
  20. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  21. 2026-10-27 21:32 UTCEchelonGraph re-scored
  22. 2026-10-27 21:32 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  23. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  24. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  25. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.3% · 27th percentile
Show 75 more
  1. 2026-10-25 14:16 UTCEchelonGraph re-scored
  2. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  3. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  4. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  5. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  6. 2026-10-20 19:03 UTCEchelonGraph re-scored
  7. 2026-10-20 19:03 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  8. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  9. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  10. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  11. 2026-10-18 03:27 UTCEchelonGraph re-scored
  12. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  13. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  14. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  15. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  16. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  17. 2026-10-13 15:53 UTCEchelonGraph re-scored
  18. 2026-10-13 15:53 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  19. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  20. 2026-10-12 15:52 UTCEchelonGraph re-scored
  21. 2026-10-11 19:36 UTCEchelonGraph re-scored
  22. 2026-10-11 16:51 UTCEchelonGraph re-scored
  23. 2026-10-11 14:13 UTCEchelonGraph re-scored
  24. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  25. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  26. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  27. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  28. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  29. 2026-10-06 23:47 UTCEchelonGraph re-scored
  30. 2026-10-06 23:47 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  31. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  32. 2026-10-05 19:50 UTCEchelonGraph re-scored
  33. 2026-10-05 19:50 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  34. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  35. 2026-10-04 23:47 UTCEchelonGraph re-scored
  36. 2026-10-04 23:47 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  37. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  38. 2026-10-04 06:22 UTCEchelonGraph re-scored
  39. 2026-10-04 06:22 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  40. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  41. 2026-10-03 02:40 UTCEchelonGraph re-scored
  42. 2026-10-03 02:40 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  43. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  44. 2026-10-02 10:25 UTCEchelonGraph re-scored
  45. 2026-10-02 10:25 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  46. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  47. 2026-10-01 14:40 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  48. 2026-10-01 02:40 UTCEchelonGraph re-scored
  49. 2026-10-01 02:39 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  50. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  51. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  52. 2026-09-29 06:44 UTCEchelonGraph re-scored
  53. 2026-09-29 06:44 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  54. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  55. 2026-09-28 06:19 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  56. 2026-09-27 18:19 UTCEchelonGraph re-scored
  57. 2026-09-27 18:19 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  58. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  59. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  60. 2026-09-25 04:48 UTCEchelonGraph re-scored
  61. 2026-09-25 04:48 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  62. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  63. 2026-09-24 09:36 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  64. 2026-09-23 21:31 UTCEchelonGraph re-scored
  65. 2026-09-23 21:31 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  66. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  67. 2026-09-23 09:30 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  68. 2026-09-22 21:30 UTCEchelonGraph re-scored
  69. 2026-09-22 21:30 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  70. 2026-09-22 05:46 UTCEchelonGraph re-scored
  71. 2026-09-22 05:46 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  72. 2026-09-20 20:58 UTCEchelonGraph re-scored
  73. 2026-09-20 20:58 UTCGHSA enrichmentGHSA-8rxj-3p7p-rq39 · GitHub severity CRITICAL · GitHub CVSS 8.6
  74. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  75. 2026-09-20 01:38 UTCEchelonGraph re-scored

Frequently asked(5)

What is CVE-2026-59638?
CVE-2026-59638 is a high-severity vulnerability; its CVE record was published on August 3, 2026. In Bouncy Castle for Java before 1.85, JSSE hostname verifier CN-fallback enabled by default despite documented opt-in. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bctls-fips 1.0.24 (1.0.X series), 2.0.24 (2.0.X series) and…
When was the CVE record for CVE-2026-59638 published?
The CVE record for CVE-2026-59638 was published on August 3, 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 August 28, 2026; the record at its source may have been updated since.
Is CVE-2026-59638 actively exploited?
CVE-2026-59638 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (28th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-59638?
CVE-2026-59638 has a CVSS v3 base score of 6.5 (NVD). EchelonGraph synthesises NVD + FIRST EPSS + GHSA into a combined EG score of 8.6 (HIGH).
How do I remediate CVE-2026-59638?
A fix for CVE-2026-59638 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-59638 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-59638

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