In Bouncy Castle for Java before 1.85, IESEngine stream-mode MAC forgery via length-dependent KDF split. This issue also affects Bouncy Castle for Java LTS before 2.73.12.
CVE-2026-12816
This high-severity CVE scores 8.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 95% 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).
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.7
- EG Score
- 8.7(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 computedSeverity87% × 45%Exploitation0% × 40%Automatability100% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 5%
- KEV
- Not listed
Published
August 3, 2026
Last Modified
August 4, 2026
Advisory Details (2)
Auto-updated Aug 3, 2026commit 6d9e4bbaee94 (bcgit/bc-java)
Fix landed in bcgit/bc-java commit 6d9e4bbaee94 — awaiting tagged release
https://github.com/bcgit/bc-java/commit/6d9e4bbaee9409713ada167e5f901554cbb084acVendor Advisories for CVE-2026-12816(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)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| bouncycastle | 1.68-2 ... 1.80-3 (12 versions) | — | — |
Debian:12(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| bouncycastle | 1.72-2, 1.77-1, 1.80-1, 1.80-2, 1.80-3 | — | — |
Debian:13(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| bouncycastle | 1.80-3 | — | — |
Debian:14(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| bouncycastle | 1.80-3 | — | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 26× in last 7d / 74× 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.
- 2026-08-20 09:46 UTCGHSA enrichment
- 2026-08-19 21:36 UTCEG score recompute
- 2026-08-19 21:36 UTCGHSA enrichment
- 2026-08-19 17:03 UTCEPSS rescore
- 2026-08-19 09:06 UTCGHSA enrichment
- 2026-08-18 20:50 UTCEG score recompute
- 2026-08-18 20:50 UTCGHSA enrichment
- 2026-08-18 13:48 UTCEPSS rescore
- 2026-08-18 08:40 UTCGHSA enrichment
- 2026-08-17 19:49 UTCEG score recompute
- 2026-08-17 19:49 UTCGHSA enrichment
- 2026-08-17 07:37 UTCGHSA enrichment
- 2026-08-16 19:27 UTCEG score recompute
- 2026-08-16 19:27 UTCGHSA enrichment
- 2026-08-16 14:56 UTCEPSS rescore
- 2026-08-16 07:16 UTCEG score recompute
- 2026-08-16 07:16 UTCGHSA enrichment
- 2026-08-16 02:14 UTCEPSS rescore
- 2026-08-15 19:06 UTCGHSA enrichment
- 2026-08-15 06:56 UTCEG score recompute
- 2026-08-15 06:56 UTCGHSA enrichment
- 2026-08-15 01:30 UTCEPSS rescore
- 2026-08-14 18:29 UTCGHSA enrichment
- 2026-08-14 06:19 UTCEG score recompute
- 2026-08-14 06:19 UTCGHSA enrichment
Show 49 moreShow fewer
- 2026-08-13 22:00 UTCEPSS rescore
- 2026-08-13 18:09 UTCGHSA enrichment
- 2026-08-13 05:58 UTCGHSA enrichment
- 2026-08-12 17:48 UTCEG score recompute
- 2026-08-12 17:48 UTCGHSA enrichment
- 2026-08-12 13:50 UTCEPSS rescore
- 2026-08-12 05:38 UTCGHSA enrichment
- 2026-08-11 17:23 UTCEG score recompute
- 2026-08-11 17:23 UTCGHSA enrichment
- 2026-08-11 13:42 UTCEPSS rescore
- 2026-08-11 05:11 UTCEG score recompute
- 2026-08-11 05:11 UTCGHSA enrichment
- 2026-08-10 23:59 UTCEPSS rescore
- 2026-08-10 17:01 UTCGHSA enrichment
- 2026-08-10 04:51 UTCGHSA enrichment
- 2026-08-09 16:41 UTCGHSA enrichment
- 2026-08-09 04:31 UTCEG score recompute
- 2026-08-09 04:31 UTCGHSA enrichment
- 2026-08-08 16:37 UTCEPSS rescore
- 2026-08-08 16:21 UTCGHSA enrichment
- 2026-08-08 04:10 UTCEG score recompute
- 2026-08-08 04:10 UTCGHSA enrichment
- 2026-08-07 16:00 UTCGHSA enrichment
- 2026-08-07 03:50 UTCGHSA enrichment
- 2026-08-06 15:40 UTCEG score recompute
- 2026-08-06 15:40 UTCGHSA enrichment
- 2026-08-06 13:46 UTCEPSS rescore
- 2026-08-06 03:29 UTCEG score recompute
- 2026-08-06 03:29 UTCGHSA enrichment
- 2026-08-05 19:17 UTCEPSS rescore
- 2026-08-05 15:19 UTCGHSA enrichment
- 2026-08-05 03:09 UTCEG score recompute
- 2026-08-05 03:09 UTCGHSA enrichment
- 2026-08-04 15:09 UTCEPSS rescore
- 2026-08-04 14:54 UTCEG score recompute
- 2026-08-04 14:54 UTCGHSA enrichment
- 2026-08-04 10:38 UTCEPSS rescore
- 2026-08-04 04:47 UTCGHSA enrichment
- 2026-08-03 16:36 UTCEG score recompute
- 2026-08-03 16:36 UTCGHSA enrichment
- 2026-08-03 15:28 UTCEG score recompute
- 2026-08-03 15:28 UTCGHSA enrichment
- 2026-08-03 07:29 UTCEG score recompute
- 2026-08-03 07:29 UTCGHSA enrichment
- 2026-08-03 06:39 UTCEG score recompute
- 2026-08-03 06:39 UTCGHSA enrichment
- 2026-08-03 04:18 UTCEG score recompute
- 2026-08-03 04:04 UTCEG score recompute
- 2026-08-03 04:03 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-12816?
When was CVE-2026-12816 disclosed?
Is CVE-2026-12816 actively exploited?
What is the CVSS score of CVE-2026-12816?
How do I remediate CVE-2026-12816?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-12816
Is Your Infrastructure Affected by CVE-2026-12816?
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