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: 0.3%CVSS: 6.5Exploit: 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.

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 54/100CISA SSVC

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%
CISA SSVC: Track at low or medium mission impact; Attend at high (mission-essential systems).
Action: An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high until it ships, then apply the release.
EPSS PROB
0.3%
EPSS %ILE
25th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Attend at high (mission-essential systems).

An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high until it ships, then apply the release.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

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 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 20× in last 7d / 89× 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 327 total refreshes for this CVE.

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

Related CVEs(same product + same CWE)

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 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 0.3% probability of exploitation in the next 30 days (25th 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 + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 8.6 (HIGH).
How do I remediate CVE-2026-59638?
An upstream fix for CVE-2026-59638 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-2026-59638 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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