{"id":"CVE-2026-69249","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-69249","generatedAt":"2026-10-28T04:43:51.332Z","title":"python-cryptography is a package designed to expose cryptographic primitives and recipes to Python developers.","description":"python-cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. In versions 42.0.0 through 48.0.0, when resolving invalid certificate chains that include duplicate copies of self-signed certificates, the processing recursively invokes the same candidate, leading to an exponential blowup. Although the limitation that the chain depth cannot exceed a specified maximum depth prevents unbounded recursion and guarantees termination, an attacker-controlled certificate chain can lead the processing to easily take more than 5s to reject in testing. This amplification could form the basis for a resource exhaustion denial of service attack. The core issue arises in the recursive nature of build_chain_inner, which does not de-duplicate against previously analyzed candidates. As the correctness of validation is not affected, the integrity of a system cannot be compromised through this vector, only its availability. This issue is fixed in 49.0.0.","published":"2026-08-03T22:16:53.000Z","lastModified":"2026-10-23T21:10:00.000Z","status":"Awaiting Analysis","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"4.0","score":8.7,"severity":"HIGH","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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/M"},"cwe":["CWE-400"],"affected":[],"epss":{"score":0.00262,"percentile":0.17865,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.26%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/pyca/cryptography/commit/3763aa79b","source":"security-advisories@github.com"},{"url":"https://github.com/pyca/cryptography/commit/4a12cf49675a184e47f912b00b04f3a629283582","source":"security-advisories@github.com"},{"url":"https://github.com/pyca/cryptography/pull/14960","source":"security-advisories@github.com"},{"url":"https://github.com/pyca/cryptography/security/advisories/GHSA-jwv3-5hgf-82ww","source":"security-advisories@github.com"},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/cryptography/PYSEC-2026-3553.yaml","source":"security-advisories@github.com"},{"url":"https://github.com/pyca/cryptography/security/advisories/GHSA-jwv3-5hgf-82ww","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-69249","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}