CVE Vulnerability Catalog

Allocation of resources without limits in password-based private-key decryption (PbeUtilities.GenerateCipherParameters) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who can supply an encrypted private key, such as a PKCS#8 EncryptedPrivateKeyInfo or "ENCRYPTED PRIVATE KEY" PEM file, to cause a denial of service through CPU exhaustion via an iteration count close to 2^31, because the count is taken from the unauthenticated algorithm parameters without an upper bound and the key derivation runs before the password or the data can be checked. PKCS#5 PBES1 and PBES2 (PBKDF2), the PKCS#12 PBE algorithms and CMS password recipients (CmsPbeKey) are affected. Loading PKCS#12 files with Pkcs12Store is covered by CVE-2026-63572, and a zero or negative count with the PKCS#12 algorithms by CVE-2026-63575.

Improper certificate validation in the directoryName name-constraint check (PkixNameConstraintValidator.WithinDNSubtree) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who controls, or can have certificates issued by, a name-constrained intermediate CA to get certificates accepted by PKIX path validation whose subject distinguished name, or a directoryName subjectAltName, lies outside the CA's permitted subtrees, via a name that places other RDNs ahead of a copy of the permitted RDN sequence, because the check looks for the constraint's first RDN anywhere in the name and compares the remaining RDNs from that position, instead of requiring the constraint to be an initial prefix of the name as RFC 5280 sections 4.2.1.10 and 7.1 require.

Improper certificate validation in PkixNameConstraintValidator (ExtractHostFromURL) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a name-constrained subordinate CA, or anyone able to obtain certificates with chosen subjectAltName URIs from such a CA, to bypass permitted or excluded uniformResourceIdentifier name constraints during certification path validation via a URI whose path, query, fragment or userinfo contains characters such as '@' or ':', because the host was extracted by string slicing without first isolating the RFC 3986 authority component, so the host compared against the constraints could differ from the URI's actual host.

Loop with unreachable exit condition in the PKCS#12 key derivation (Pkcs12ParametersGenerator) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who can supply a PKCS#12 (PFX) file, or a PKCS#8 encrypted private key that uses a PKCS#12 password-based encryption algorithm, to cause a denial of service through CPU exhaustion via an iteration count of zero or below, because the derivation loop ran until its counter equalled the count, so for such a count it wrapped through about 2^32 iterations before the MAC or the password could be checked. A 75-byte PFX file with a negative MacData iteration count kept Pkcs12Store.Load busy for many minutes.

Memory allocation with excessive size value in the OpenPGP signature and user attribute subpacket parsers (SignatureSubpacketsParser.ReadPacket, UserAttributeSubpacketsParser.ReadPacket) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote, unauthenticated attacker who can supply a crafted OpenPGP public key, certificate or signature to cause a denial of service (OutOfMemoryException or memory exhaustion in the parsing process) via a subpacket header using the five-octet length form, because the declared length was used to size the subpacket buffer with no upper bound and without being compared with the size of the enclosing subpacket area or packet, so a few bytes of input could demand an allocation of up to about 2 GB before any subpacket data was read.

Observable discrepancy in the CMS RSA PKCS#1 v1.5 key-transport unwrap (KeyTransRecipientInformation.UnwrapKey) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote attacker who holds a captured CMS EnvelopedData message, and who can submit many modified messages to an application that decrypts them with the recipient's RSA private key and reveals how decryption failed, to recover the captured message's content-encryption key and so its content, via a Bleichenbacher-style adaptive chosen-ciphertext attack, because a key-transport ciphertext with invalid PKCS#1 v1.5 padding is rejected during unwrap with a distinct "bad padding in message." CmsException instead of being replaced by a random key, so it can be told apart from a correctly padded ciphertext, which fails only later at content decryption.

Allocation of resources without limits in PKCS#12 keystore loading (Pkcs12Store.Load) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who can supply a PKCS#12 (PFX) file to cause a denial of service through CPU exhaustion via an iteration count close to 2^31 in the file's MacData or in the PBE parameters of an encrypted SafeContents or shrouded key bag, because the counts are taken from the file without an upper bound and the key derivation runs before the MAC or the password can be checked. A zero or negative count is covered by CVE-2026-63575. Pkcs12Utilities.ConvertToDefiniteLength is also affected.

Improper verification of cryptographic signature in the attribute certificate path validator (PkixAttrCertPathValidator, also used by PkixAttrCertPathBuilder) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote attacker to have a forged X.509 attribute certificate accepted as valid, and so obtain whatever roles or privileges an application grants on the strength of its attributes, via an attribute certificate that names a trusted attribute authority as its issuer but was not signed by it, because the RFC 3281 validation steps check the holder and issuer certification paths, validity period, extensions and revocation status but never verify the attribute certificate's signature with the issuer's public key. Only applications that use these classes to validate attribute certificates are affected.

A vulnerability in the bc-csharp library (Bouncy Castle for .NET) in Pkcs12Store.GetCertificateChain involves a loop with an unreachable exit condition. An attacker can supply a crafted PKCS#12 file where the certificate chain forms a cycle (e.g., two certificates whose AuthorityKeyIdentifier extensions reference each other's public key), causing the application to hang and exhaust memory until an OutOfMemoryException occurs.

A side-channel vulnerability exists in the NTRU implementation of Bouncy Castle for Java before version 1.86. The reduction of secret values using the % operator in three helper functions causes execution time to depend on the secret operand (division by a variable), potentially allowing an attacker to recover information about the NTRU private key through timing measurements.

In the MLS implementation (RFC 9420) of Bouncy Castle for Java before 1.86, the uint32 leaf_index is stored as a signed int, allowing a wire value with the top bit set to decode as a negative number. Incorrect comparison in GroupKeySet.SecretTree.hasLeaf and Group.validateRemove allows bypassing membership checks, potentially leading to a DoS attack via unbounded growth of the node list and JVM heap exhaustion.

Inefficient algorithmic complexity in X.509 distinguished name string conversion (X509Name.ToString and IetfUtilities.ValueToString) in Bouncy Castle for .NET (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 requiring escaping (e.g., commas, leading/trailing spaces), causing quadratic growth in processing time.

Memory allocation with excessive size value in the HSS/LMS signature code (HssPublicKeyParameters, HssSignature) in Bouncy Castle for .NET (bc-csharp) before 2.7.0 allows a remote unauthenticated attacker to cause a denial of service through memory exhaustion via a public key encoding with an excessive level count (L), leading to allocation of an array of size L-1 and memory exhaustion (up to ~17 GB) or OutOfMemoryException.

Improper certificate validation in PkixNameConstraintValidator in Bouncy Castle for .NET (bc-csharp) before 2.7.0 allows an attacker who controls or can obtain certificates from a name-constrained intermediate CA to have certificates accepted for email addresses, DNS names, or URI hosts within excluded subtrees, via names ending with a dot (e.g., rfc822Name, dNSName, uniformResourceIdentifier), because comparison does not remove the trailing root-label dot per RFC 1034.

Release of unverified plaintext in the CCM (CcmBlockCipher) and DSTU 7624 CCM (KCcmBlockCipher) AEAD modes in Bouncy Castle for .NET (bc-csharp) before 2.7.0 allows a remote attacker to obtain decryptions of chosen ciphertexts via forged messages sent to an application that lets the output buffer of a failed decryption be observed (e.g., through buffer reuse or logging), because decryption writes recovered plaintext into the caller-supplied output buffer before checking the authentication tag and leaves it there on failure.

Uncontrolled recursion in the ASN.1 parser (Asn1InputStream, Asn1StreamParser) in Bouncy Castle for .NET (bc-csharp) before 2.7.0 allows a remote unauthenticated attacker to cause a denial of service via crafted ASN.1 encoding of deeply nested constructed elements (e.g., SEQUENCE inside SEQUENCE), because each nesting level is parsed by a further recursive call with no depth bound. About 2,000 levels (8 KB DER) are enough to exhaust a 1.5 MB thread stack and raise a StackOverflowException, which .NET cannot catch and which terminates the whole process.

The Relevanssi Premium plugin for WordPress in versions up to and including 2.31.4 is vulnerable to stored cross-site scripting (XSS) via the '_rt' parameter due to insufficient input sanitization and output escaping. An unauthenticated attacker can inject arbitrary scripts into pages that execute when a user visits the injected page. This requires the click-tracking and logging feature to be enabled, and exploitation is trivial because a valid '_rt_nonce' is publicly emitted on every search-results page.

The CMB2 plugin for WordPress in versions up to and including 2.13.1 is vulnerable to stored cross-site scripting (XSS) via the '<textarea_code field id>' parameter (e.g., kl_code, kl_post_code) due to insufficient input sanitization and output escaping. An unauthenticated attacker can inject arbitrary scripts into pages that execute when a user visits the injected page. The front-end save path requires only a CMB2 box nonce, which is emitted to all visitors including unauthenticated guests via a simple GET request, making the attack trivially reachable without credentials on sites exposing a public CMB2 form writing a textarea_code field.

The Download Monitor plugin for WordPress is vulnerable to stored XSS via postMessage to the admin editor. Insufficient input sanitization and output escaping allow unauthenticated attackers to inject scripts that execute when a user accesses an injected page.

The Kubio AI Page Builder plugin for WordPress is vulnerable to stored XSS via the 'comment' parameter. Insufficient input sanitization and output escaping allow unauthenticated attackers to inject scripts that execute when a user accesses an injected page.