CVE-2026-59638

CRITICALPre-NVD 9.39.3—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 80% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 3 sources updated this week
9.3EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.3Exploit: None knownExposed: 0

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

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
9.3
EG Score
9.3(medium)
EG Risk
57(Track)
EG Risk 57/100SSVC: 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
Severity93% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
20%
KEV
Not listed

Published

August 3, 2026

Last Modified

August 4, 2026

Advisory Details (3)

Auto-updated Aug 3, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
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
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
generic

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 rangeFixed inDependents
bouncycastle1.68-2 ... 1.80-3 (12 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
bouncycastle1.72-2, 1.77-1, 1.80-1, 1.80-2, 1.80-3——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
bouncycastle1.80-3——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
bouncycastle1.80-3——

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 58× in last 7d / 156× 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.

Showing the most recent 100 of 156 total refreshes for this CVE.

  1. 2026-08-21 05:28 UTCGHSA enrichment
  2. 2026-08-21 01:42 UTCEG score recompute
  3. 2026-08-21 01:42 UTCGHSA enrichment
  4. 2026-08-20 22:55 UTCEPSS rescore
  5. 2026-08-20 21:56 UTCGHSA enrichment
  6. 2026-08-20 18:10 UTCGHSA enrichment
  7. 2026-08-20 14:22 UTCGHSA enrichment
  8. 2026-08-20 10:14 UTCGHSA enrichment
  9. 2026-08-20 06:29 UTCGHSA enrichment
  10. 2026-08-20 02:43 UTCGHSA enrichment
  11. 2026-08-19 22:47 UTCGHSA enrichment
  12. 2026-08-19 19:01 UTCEG score recompute
  13. 2026-08-19 19:01 UTCGHSA enrichment
  14. 2026-08-19 17:04 UTCEPSS rescore
  15. 2026-08-19 14:40 UTCGHSA enrichment
  16. 2026-08-19 10:55 UTCGHSA enrichment
  17. 2026-08-19 07:09 UTCGHSA enrichment
  18. 2026-08-19 03:23 UTCGHSA enrichment
  19. 2026-08-18 23:20 UTCGHSA enrichment
  20. 2026-08-18 19:35 UTCGHSA enrichment
  21. 2026-08-18 15:49 UTCEG score recompute
  22. 2026-08-18 15:49 UTCGHSA enrichment
  23. 2026-08-18 13:48 UTCEPSS rescore
  24. 2026-08-18 11:41 UTCGHSA enrichment
  25. 2026-08-18 07:55 UTCGHSA enrichment
Show 75 more
  1. 2026-08-18 04:09 UTCGHSA enrichment
  2. 2026-08-18 00:20 UTCGHSA enrichment
  3. 2026-08-17 20:19 UTCGHSA enrichment
  4. 2026-08-17 16:33 UTCEG score recompute
  5. 2026-08-17 16:33 UTCGHSA enrichment
  6. 2026-08-17 13:47 UTCEPSS rescore
  7. 2026-08-17 12:28 UTCGHSA enrichment
  8. 2026-08-17 08:43 UTCGHSA enrichment
  9. 2026-08-17 04:58 UTCGHSA enrichment
  10. 2026-08-17 01:12 UTCGHSA enrichment
  11. 2026-08-16 21:26 UTCGHSA enrichment
  12. 2026-08-16 17:40 UTCEG score recompute
  13. 2026-08-16 17:40 UTCGHSA enrichment
  14. 2026-08-16 14:56 UTCEPSS rescore
  15. 2026-08-16 13:44 UTCGHSA enrichment
  16. 2026-08-16 09:58 UTCGHSA enrichment
  17. 2026-08-16 06:13 UTCGHSA enrichment
  18. 2026-08-16 02:28 UTCEG score recompute
  19. 2026-08-16 02:28 UTCGHSA enrichment
  20. 2026-08-16 02:14 UTCEPSS rescore
  21. 2026-08-15 22:43 UTCGHSA enrichment
  22. 2026-08-15 18:57 UTCGHSA enrichment
  23. 2026-08-15 15:11 UTCGHSA enrichment
  24. 2026-08-15 11:25 UTCGHSA enrichment
  25. 2026-08-15 07:39 UTCGHSA enrichment
  26. 2026-08-15 03:53 UTCEG score recompute
  27. 2026-08-15 03:53 UTCGHSA enrichment
  28. 2026-08-15 01:30 UTCEPSS rescore
  29. 2026-08-15 00:07 UTCGHSA enrichment
  30. 2026-08-14 20:21 UTCGHSA enrichment
  31. 2026-08-14 16:36 UTCGHSA enrichment
  32. 2026-08-14 12:40 UTCGHSA enrichment
  33. 2026-08-14 08:55 UTCGHSA enrichment
  34. 2026-08-14 05:09 UTCGHSA enrichment
  35. 2026-08-14 01:23 UTCEG score recompute
  36. 2026-08-14 01:23 UTCGHSA enrichment
  37. 2026-08-13 22:00 UTCEPSS rescore
  38. 2026-08-13 21:38 UTCGHSA enrichment
  39. 2026-08-13 17:52 UTCGHSA enrichment
  40. 2026-08-13 14:01 UTCGHSA enrichment
  41. 2026-08-13 10:16 UTCGHSA enrichment
  42. 2026-08-13 06:30 UTCGHSA enrichment
  43. 2026-08-13 02:45 UTCGHSA enrichment
  44. 2026-08-12 22:59 UTCGHSA enrichment
  45. 2026-08-12 19:14 UTCGHSA enrichment
  46. 2026-08-12 15:29 UTCEG score recompute
  47. 2026-08-12 15:28 UTCGHSA enrichment
  48. 2026-08-12 13:51 UTCEPSS rescore
  49. 2026-08-12 11:39 UTCGHSA enrichment
  50. 2026-08-12 07:53 UTCGHSA enrichment
  51. 2026-08-12 04:08 UTCGHSA enrichment
  52. 2026-08-12 00:22 UTCGHSA enrichment
  53. 2026-08-11 20:33 UTCGHSA enrichment
  54. 2026-08-11 16:48 UTCEG score recompute
  55. 2026-08-11 16:48 UTCGHSA enrichment
  56. 2026-08-11 13:02 UTCGHSA enrichment
  57. 2026-08-11 09:16 UTCGHSA enrichment
  58. 2026-08-11 05:31 UTCGHSA enrichment
  59. 2026-08-11 01:45 UTCEG score recompute
  60. 2026-08-11 01:45 UTCGHSA enrichment
  61. 2026-08-11 00:00 UTCEPSS rescore
  62. 2026-08-10 22:00 UTCGHSA enrichment
  63. 2026-08-10 18:14 UTCGHSA enrichment
  64. 2026-08-10 14:28 UTCGHSA enrichment
  65. 2026-08-10 10:43 UTCGHSA enrichment
  66. 2026-08-10 06:56 UTCGHSA enrichment
  67. 2026-08-10 03:11 UTCGHSA enrichment
  68. 2026-08-09 23:25 UTCGHSA enrichment
  69. 2026-08-09 19:40 UTCGHSA enrichment
  70. 2026-08-09 15:54 UTCEG score recompute
  71. 2026-08-09 15:54 UTCGHSA enrichment
  72. 2026-08-09 13:46 UTCEPSS rescore
  73. 2026-08-09 12:09 UTCGHSA enrichment
  74. 2026-08-09 08:23 UTCGHSA enrichment
  75. 2026-08-09 04:38 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-59638?
CVE-2026-59638 is a critical vulnerability 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 CVE-2026-59638 disclosed?
CVE-2026-59638 was first published in the National Vulnerability Database on August 3, 2026, with the most recent update on August 4, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-59638 actively exploited?
CVE-2026-59638 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 79.8% of all scored CVEs.
What is the CVSS score of CVE-2026-59638?
CVE-2026-59638 has a CVSS v3 base score of 9.3 (NVD).
How do I remediate CVE-2026-59638?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-59638, 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

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

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