7.5High
Bouncycastle Bc-Java
CVE-2026-12802
In Bouncy Castle for Java before 1.85, CMS AuthEnvelopedData fails to enforce tag-length on decryption. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.12 (1.0.X series), 2.0.12 (2.0.X series) and 2.1.12 (2.1.X series).
What this means for your business
- It affects Bouncycastle Bc-Java. It matters if your company, or a supplier that handles your data, runs it.
- An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.1% chance of attack attempts being seen in the next 30 days, ranking above 4% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Bouncycastle Bc-Java, and which version. The affected versions are listed further down this page.
- 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.
Not sure if your company is exposed?
Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.
Scoring
- CVSS
- 7.5 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N- CVSS v4
- 8.7
- Weakness
- CWE-354
- Assigned by
- 91579145-5d7b-4cc5-b925-a0262ff19630
Dates
- Published
- 2026-08-03
- Last modified
- 2026-09-02
- Sources
- NVD
Affected products
- Bouncycastle Bc-Java- 1.85
- Bouncycastle Bcpkix-Fips- 1.0.12, 2.0.7 - 2.0.12, 2.1.8 - 2.1.12
- Bouncycastle Bouncy Castle For Java Lts- 2.73.11
As listed in the NVD configuration data. Not a statement about your estate.