CVE-2026-103604

Inefficient algorithmic complexity in X.509 distinguished name string conversion (X509Name.ToString and IetfUtilities.ValueToString) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote unauthenticated attacker to cause a denial of service through CPU exhaustion via a certificate, CRL, certification request or other structure whose name contains a long attribute value made up of characters that must be escaped, such as commas, or of leading or trailing spaces, because each escaping backslash was inserted into the buffer being scanned, so the work grew quadratically with the length of the value. Applications are exposed when they convert such a name to a string, for example to log or display it, or compare it with IetfUtilities.RdnAreEqual, as PKIX path validation does for directoryName name constraints.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/bcgit/bc-csharp/commit/bd03e38bbb49db5be33f4463fc40997400c545cc	Patch
https://github.com/bcgit/bc-csharp/wiki/CVE-2026-103604	Patch Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:bouncycastle:bc-csharp:*:*:*:*:*:*:*:*

History

28 Oct 2026, 13:27

Type	Values Removed	Values Added
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 7.5
References	~~() https://github.com/bcgit/bc-csharp/commit/bd03e38bbb49db5be33f4463fc40997400c545cc -~~	() https://github.com/bcgit/bc-csharp/commit/bd03e38bbb49db5be33f4463fc40997400c545cc - Patch
References	~~() https://github.com/bcgit/bc-csharp/wiki/CVE-2026-103604 -~~	() https://github.com/bcgit/bc-csharp/wiki/CVE-2026-103604 - Patch, Vendor Advisory
CPE		cpe:2.3:a:bouncycastle:bc-csharp::::::::
First Time		Bouncycastle bc-csharp Bouncycastle

02 Oct 2026, 08:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-02 08:17

Updated : 2026-10-28 13:27

NVD link : CVE-2026-103604

Mitre link : CVE-2026-103604

CVE.ORG link : CVE-2026-103604

JSON object : View

Products Affected

bouncycastle

bc-csharp

CWE

CWE-407

Inefficient Algorithmic Complexity

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