8.7
HIGH CVSS 4.0
CVE-2026-12860
RSA PKCS#1 verification skips last two hash bytes in NULL-omitted path
Description

In Bouncy Castle for Java before 1.85, RSA PKCS#1 verification skips last two hash bytes in NULL-omitted path. This issue also affects Bouncy Castle for Java LTS before 2.73.12.

INFO

Published Date :

Aug. 3, 2026, 4:16 a.m.

Last Modified :

Aug. 3, 2026, 4:16 a.m.

Remotely Exploit :

Yes !

Source :

91579145-5d7b-4cc5-b925-a0262ff19630
Affected Products

The following products are affected by CVE-2026-12860 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 HIGH 91579145-5d7b-4cc5-b925-a0262ff19630
CVSS 4.0 HIGH 91579145-5d7b-4cc5-b925-a0262ff19630
Solution
Update Bouncy Castle for Java to a patched version to correct RSA PKCS#1 verification.
  • Update Bouncy Castle for Java to 1.85 or later.
  • Update Bouncy Castle for Java LTS to 2.73.12 or later.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-12860.

URL Resource
https://github.com/bcgit/bc-java/commit/ea5970ea9b2fb91d763b904692fd21089ca3e396
https://github.com/bcgit/bc-java/wiki/CVE-2026-12860
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-12860 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-12860 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-12860 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-12860 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by 91579145-5d7b-4cc5-b925-a0262ff19630

    Aug. 03, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://github.com/bcgit/bc-java', 'vendor': 'Legion of the Bouncy Castle Inc.', 'modules': ['core'], 'product': 'BC-JAVA', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '1.85', 'versionType': 'maven'}], 'platforms': ['all'], 'packageURL': 'pkg:maven/org.bouncycastle/bcprov-jdk18on', 'packageName': 'bcprov', 'programFiles': ['RSADigestSigner'], 'collectionURL': 'https://www.bouncycastle.org/download/bouncy-castle-java/', 'defaultStatus': 'unaffected'}, {'repo': 'https://github.com/bcgit/bc-lts-java', 'vendor': 'Legion of the Bouncy Castle Inc.', 'modules': ['core'], 'product': 'BC-LTS-JAVA', 'versions': [{'status': 'affected', 'version': '2.73.0', 'lessThan': '2.73.12', 'versionType': 'maven'}], 'platforms': ['all'], 'packageURL': 'pkg:maven/org.bouncycastle/bcprov-lts8on', 'packageName': 'bcprov-lts8on', 'programFiles': ['RSADigestSigner'], 'collectionURL': 'https://www.bouncycastle.org/download/bouncy-castle-java-lts/', 'defaultStatus': 'unaffected'}]
    Added Description In Bouncy Castle for Java before 1.85, RSA PKCS#1 verification skips last two hash bytes in NULL-omitted path. This issue also affects Bouncy Castle for Java LTS before 2.73.12.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber
    Added CWE CWE-347
    Added Reference https://github.com/bcgit/bc-java/commit/ea5970ea9b2fb91d763b904692fd21089ca3e396
    Added Reference https://github.com/bcgit/bc-java/wiki/CVE-2026-12860
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.