{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-63567 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-63567 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-63567 is a high-severity vulnerability in Legion of the Bouncy Castle Inc. bc-csharp, published on 2 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-63567 and fix it if it is affected.\n\nWhat it is: CVE-2026-63567 is a high-severity vulnerability in Legion of the Bouncy Castle Inc. bc-csharp, published on 2 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-63567 in the wild and no public exploit code.\n\nAffected product: Legion of the Bouncy Castle Inc. bc-csharp. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-63567/ (Markdown: https://insights.sbomify.com/CVE-2026-63567/index.md)","id":"CVE-2026-63567","markdown":"https://insights.sbomify.com/CVE-2026-63567/index.md","name":"CVE-2026-63567","record":{"aliases":["GHSA-6w4x-4wpp-m6r4"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_read"],"network_reachable":"yes","non_default_config":true,"product_category":"C# cryptography library","requires_auth":"none","summary":"Remote attackers can recover plaintext from IES/ECIES ciphertexts via a padding oracle attack in Bouncy Castle C# when using padded block ciphers.","user_interaction":"not_required","vuln_class":"weak_cryptography"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"bcorg","cpe":[{"product":"bc-csharp","vendor":"bouncycastle"}],"cvss":{"score":8.2,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-203","name":"Observable Discrepancy"}],"description":"Observable discrepancy in IesEngine.DecryptBlock in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote attacker who has captured an IES or ECIES ciphertext, and who can submit modified ciphertexts for decryption under the same key pair, to recover its plaintext via a CBC padding-oracle attack, because in block-cipher mode the engine decrypts the ciphertext and removes its padding before verifying the MAC. A padding failure is therefore reported with a different error message, and without the MAC computation, compared with a MAC failure. Only applications that construct IesEngine directly with a padded block cipher, such as AES in CBC mode with PKCS#7 padding, are affected; stream-mode IES is not.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":false,"headline":"IesEngine block-cipher mode checks padding before MAC (CBC padding oracle)","id":"CVE-2026-63567","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"weak_cryptography","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"Unbounded CMP/CRMF password-based MAC iteration count allows CPU exhaustion","id":"CVE-2026-63568"},"packages":[],"prev":{"headline":"DTLS handshake reassembler allocates buffer from unchecked 24-bit length","id":"CVE-2026-63566"},"products":["bc-csharp"],"published":"2026-10-02","related":[{"cvss_score":9.1,"headline":"MTI/A0 DHAgreement does not validate the peer's ephemeral value","id":"CVE-2026-63569","kev_date_added":null,"published":"2026-10-02"},{"cvss_score":8.7,"headline":"Unbounded ASN.1 nesting depth causes process-terminating stack overflow","id":"CVE-2026-103600","kev_date_added":null,"published":"2026-10-02"},{"cvss_score":8.7,"headline":"Unbounded HSS public key level count allows huge array allocation during signature verification","id":"CVE-2026-103603","kev_date_added":null,"published":"2026-10-02"},{"cvss_score":8.7,"headline":"Quadratic-time escaping when converting X.509 distinguished names to strings","id":"CVE-2026-103604","kev_date_added":null,"published":"2026-10-02"},{"cvss_score":8.7,"headline":"KCcmBlockCipher (DSTU 7624 CCM) tag not bound to nonce when no associated data is used","id":"CVE-2026-16000","kev_date_added":null,"published":"2026-10-02"},{"cvss_score":8.7,"headline":"DTLS handshake reassembler allocates buffer from unchecked 24-bit length","id":"CVE-2026-63566","kev_date_added":null,"published":"2026-10-02"},{"cvss_score":8.7,"headline":"Unbounded CMP/CRMF password-based MAC iteration count allows CPU exhaustion","id":"CVE-2026-63568","kev_date_added":null,"published":"2026-10-02"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-02","vendors":["Legion of the Bouncy Castle Inc."]},"summary":"Remote attackers can recover plaintext from IES/ECIES ciphertexts via a padding oracle attack in Bouncy Castle C# when using padded block ciphers.","url":"https://insights.sbomify.com/CVE-2026-63567/"}