Vulnerability · 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.
Published Oct 2, 2026 · catalog updated Oct 28, 2026 · Inefficient algorithmic complexity in
Last checked Oct 28, 2026. A connected source was read within the last 7 days.
Check if you run it
No confirmed exploitation is on record for CVE-2026-103604. EPSS is 0.31%. Act only if a listed version of Inefficient algorithmic complexity in is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (Inefficient algorithmic complexity in).
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
Same product and reporting
- CVE-2026-63578 · High
- CVE-2026-63577 · High
- CVE-2026-63576 · High
- CVE-2026-63575 · High
- CVE-2026-63574 · High
- Severity
- High8.7
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.31%
- Remediation
- Version ranges on file
- Affected products
- cpe bouncycastle/bc-csharp
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.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe bouncycastle/bc-csharp< 2.7.0
How to fix CVE-2026-103604
Upgrade
CVE-2026-103604 lists a fix boundary at 2.7.0. Compare the installed build with that boundary before you change production.
Version check
Affected < 2.7.0
Advisory
Open the cve_org record and follow its fix.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-103604. EPSS is 0.31%. Act only if a listed version of Inefficient algorithmic complexity in is installed.
Which versions are affected?
Compare what you have installed with < 2.7.0. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-407. EPSS 0.31%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Oct 2, 2026 · NIST NVD
Detected
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
Oct 28, 2026 · NIST NVD
Updated
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
Sources
- CVE.orgVulnerability recordCVE-2026-103604
Official CVE identifier
cve.org - NIST NVDVulnerability recordCVE-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 exhaus
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 28, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.
- CVE.orgOct 28, 2026
- NIST NVDOct 28, 2026