CVE-2026-59638

HIGHNVD 6.58.6▲
EchelonGraph scoreMEDIUM confidence

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, ghsa, nvd
Trending — 3 sources updated this week
8.6EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: 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
6.5
EG Score
8.6(medium)
EG Risk
54(Track)
EG Risk 54/100SSVC: 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
Severity86% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
12%
KEV
Not listed

Published

August 3, 2026

Last Modified

August 28, 2026

Advisory Details (4)

Auto-updated Aug 23, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
generic

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
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 25× in last 7d / 136× 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 284 total refreshes for this CVE.

  1. 2026-09-19 01:23 UTCEG score recompute
  2. 2026-09-19 01:23 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 13:20 UTCGHSA enrichment
  5. 2026-09-18 01:13 UTCEG score recompute
  6. 2026-09-18 01:13 UTCGHSA enrichment
  7. 2026-09-17 19:31 UTCEPSS rescore
  8. 2026-09-17 01:16 UTCEG score recompute
  9. 2026-09-17 01:16 UTCGHSA enrichment
  10. 2026-09-16 14:08 UTCEPSS rescore
  11. 2026-09-16 05:20 UTCEG score recompute
  12. 2026-09-16 05:20 UTCGHSA enrichment
  13. 2026-09-16 05:15 UTCEPSS rescore
  14. 2026-09-15 17:09 UTCEG score recompute
  15. 2026-09-15 17:09 UTCGHSA enrichment
  16. 2026-09-15 03:11 UTCEPSS rescore
  17. 2026-09-15 02:05 UTCGHSA enrichment
  18. 2026-09-14 08:28 UTCGHSA enrichment
  19. 2026-09-13 20:27 UTCEG score recompute
  20. 2026-09-13 20:27 UTCGHSA enrichment
  21. 2026-09-13 16:47 UTCEPSS rescore
  22. 2026-09-13 08:26 UTCGHSA enrichment
  23. 2026-09-12 20:26 UTCEG score recompute
  24. 2026-09-12 20:26 UTCGHSA enrichment
  25. 2026-09-12 08:25 UTCGHSA enrichment
Show 75 more
  1. 2026-09-11 20:24 UTCEG score recompute
  2. 2026-09-11 20:24 UTCGHSA enrichment
  3. 2026-09-11 14:53 UTCEPSS rescore
  4. 2026-09-11 07:47 UTCGHSA enrichment
  5. 2026-09-10 19:46 UTCEG score recompute
  6. 2026-09-10 19:46 UTCGHSA enrichment
  7. 2026-09-10 09:35 UTCEPSS rescore
  8. 2026-09-10 07:43 UTCGHSA enrichment
  9. 2026-09-09 19:42 UTCGHSA enrichment
  10. 2026-09-09 06:51 UTCEG score recompute
  11. 2026-09-09 06:51 UTCGHSA enrichment
  12. 2026-09-08 22:01 UTCEPSS rescore
  13. 2026-09-07 19:04 UTCEG score recompute
  14. 2026-09-07 19:04 UTCGHSA enrichment
  15. 2026-09-07 16:01 UTCEPSS rescore
  16. 2026-09-06 18:43 UTCEG score recompute
  17. 2026-09-06 18:43 UTCGHSA enrichment
  18. 2026-09-06 13:47 UTCEPSS rescore
  19. 2026-09-06 06:42 UTCGHSA enrichment
  20. 2026-09-05 18:41 UTCEG score recompute
  21. 2026-09-05 18:41 UTCGHSA enrichment
  22. 2026-09-05 04:31 UTCEG score recompute
  23. 2026-09-05 04:31 UTCGHSA enrichment
  24. 2026-09-04 10:19 UTCEG score recompute
  25. 2026-09-04 10:18 UTCGHSA enrichment
  26. 2026-09-04 05:07 UTCEPSS rescore
  27. 2026-09-03 21:09 UTCGHSA enrichment
  28. 2026-09-03 08:59 UTCEG score recompute
  29. 2026-09-03 08:59 UTCGHSA enrichment
  30. 2026-09-02 14:12 UTCEPSS rescore
  31. 2026-09-01 22:21 UTCEG score recompute
  32. 2026-09-01 22:21 UTCGHSA enrichment
  33. 2026-09-01 13:54 UTCEPSS rescore
  34. 2026-09-01 04:40 UTCEPSS rescore
  35. 2026-08-31 23:16 UTCGHSA enrichment
  36. 2026-08-30 22:09 UTCEG score recompute
  37. 2026-08-30 22:09 UTCGHSA enrichment
  38. 2026-08-30 19:17 UTCEPSS rescore
  39. 2026-08-30 10:09 UTCEG score recompute
  40. 2026-08-30 10:09 UTCGHSA enrichment
  41. 2026-08-30 01:22 UTCEPSS rescore
  42. 2026-08-29 22:07 UTCEG score recompute
  43. 2026-08-29 22:07 UTCGHSA enrichment
  44. 2026-08-28 21:42 UTCEPSS rescore
  45. 2026-08-28 17:38 UTCEG score recompute
  46. 2026-08-28 17:38 UTCGHSA enrichment
  47. 2026-08-28 17:31 UTCNVD updateCVSS v3 → 6.5 · severity → MEDIUM
  48. 2026-08-28 15:08 UTCEG score recompute▼ 0.70
  49. 2026-08-28 15:07 UTCGHSA enrichment
  50. 2026-08-28 15:06 UTCNVD updateCVSS v3 → 8.6 · severity → HIGH
  51. 2026-08-28 03:37 UTCGHSA enrichment
  52. 2026-08-27 23:51 UTCGHSA enrichment
  53. 2026-08-27 20:06 UTCEG score recompute
  54. 2026-08-27 20:05 UTCGHSA enrichment
  55. 2026-08-27 14:25 UTCEPSS rescore
  56. 2026-08-27 12:30 UTCGHSA enrichment
  57. 2026-08-27 08:44 UTCGHSA enrichment
  58. 2026-08-27 02:45 UTCGHSA enrichment
  59. 2026-08-26 22:59 UTCGHSA enrichment
  60. 2026-08-26 19:13 UTCEG score recompute
  61. 2026-08-26 19:13 UTCGHSA enrichment
  62. 2026-08-26 14:46 UTCEPSS rescore
  63. 2026-08-26 11:56 UTCGHSA enrichment
  64. 2026-08-26 08:10 UTCGHSA enrichment
  65. 2026-08-26 04:24 UTCGHSA enrichment
  66. 2026-08-26 00:33 UTCGHSA enrichment
  67. 2026-08-25 20:43 UTCGHSA enrichment
  68. 2026-08-25 16:38 UTCEG score recompute
  69. 2026-08-25 16:38 UTCGHSA enrichment
  70. 2026-08-25 13:49 UTCEPSS rescore
  71. 2026-08-25 12:42 UTCGHSA enrichment
  72. 2026-08-25 08:56 UTCGHSA enrichment
  73. 2026-08-25 05:10 UTCGHSA enrichment
  74. 2026-08-25 01:25 UTCGHSA enrichment
  75. 2026-08-24 21:39 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-59638?
CVE-2026-59638 is a high 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 28, 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 88.4% of all 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 + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 8.6.
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

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