{"id":"CVE-2026-100836","title":"Contrast through 1.20.0 contains a panic vulnerability in the transit-engine endpoint's ciphertextContainer.UnmarshalJSON function that fails to validate decoded ciphertext length before slicing","summary":"Contrast through 1.20.0 contains a panic vulnerability in the transit-engine endpoint's ciphertextContainer.UnmarshalJSON function that fails to validate decoded ciphertext length before slicing. An authenticated workload with a valid me…","severity":"medium","cvss":4.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","cwe":["CWE-129"],"vendor":"edgelesssys","product":"contrast","affected":["contrast <= 1.20.0"],"patched":["github.com/edgelesssys/contrast 1.21.0"],"published":"2026-09-27","updated":"2026-09-28","sourceUpdated":"2026-09-28T16:17:11.160","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-100836","references":[{"url":"https://github.com/edgelesssys/contrast/security/advisories/GHSA-3ccm-4qq2-5wrp","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/edgeless-systems-contrast-through-1.20.0-denial-of-service-via-ciphertextcontainer","label":"disclosure@vulncheck.com"},{"url":"https://github.com/edgelesssys/contrast/security/advisories/GHSA-3ccm-4qq2-5wrp","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://github.com/edgelesssys/contrast/commit/d6584fbff816037472034f7ad6e08cdbab1d870d"},{"url":"https://github.com/edgelesssys/contrast"},{"url":"https://github.com/edgelesssys/contrast/releases/tag/v1.21.0"}],"tags":["nvd","cve.org","exploit-available","osv","go"],"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-28T16:00:31.401784Z"},"aliases":["GHSA-3ccm-4qq2-5wrp","GO-2026-5864"],"ecosystem":"go","ingestedAt":"2026-09-27T02:41:45.570Z","epss":0.00177,"epssPercentile":0.07248,"slug":"CVE-2026-100836","body":"## Overview\n\nContrast through 1.20.0 contains a panic vulnerability in the transit-engine endpoint's ciphertextContainer.UnmarshalJSON function that fails to validate decoded ciphertext length before slicing. An authenticated workload with a valid mesh certificate can trigger a runtime panic by submitting a short base64-encoded ciphertext, causing log spam and request failures without crashing the process.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-100836)\n\nAffected packages:\n\n- `github.com/edgelesssys/contrast < 1.21.0`\n\nPatched in:\n\n- `github.com/edgelesssys/contrast 1.21.0`\n\nSource: https://osv.dev/vulnerability/GHSA-3ccm-4qq2-5wrp","depth":"twilight","depthScore":36,"depthScoreParts":{"impact":23.7,"likelihood":0,"exploitation":12,"ransomware":0},"changes":[{"seq":212003,"id":"CVE-2026-100836","ts":1790612176332,"field":"exploit_available","old":"false","new":"true"}]}