{"id":"CVE-2026-42420","aliases":["EUVD-2026-26123","GHSA-ccx3-fw7q-rr2r"],"status":"published","title":"OpenClaw \u003c 2026.4.8 - Improper Base64 Decoding Size Validation","description":"OpenClaw before 2026.4.8 contains improper input validation in base64 decode paths that allocate memory before enforcing decoded-size limits. Attackers can exploit multiple code paths to cause memory exhaustion or denial of service through crafted base64-encoded input.","severity":{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00302,"percentile":0.23133,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-770"],"published":"2026-04-09T17:37:20Z","modified":"2026-10-28T02:31:02Z","fixes":[{"ecosystem":"npm","package":"openclaw","fixed_in":["2026.4.8"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"openclaw","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2026.4.8"}]}]},{"source":"osv","ecosystem":"npm","package":"openclaw","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2026.4.8"}]}]}],"products":[{"vendor":"openclaw","product":"openclaw"}],"references":[{"url":"https://github.com/openclaw/openclaw/security/advisories/GHSA-ccx3-fw7q-rr2r","tags":["vendor-advisory","Vendor Advisory","advisory","web"]},{"url":"https://github.com/openclaw/openclaw/commit/d7c3210cd6f5fdfdc1beff4c9541673e814354d5","tags":["patch","Patch","fix","web"]},{"url":"https://www.vulncheck.com/advisories/openclaw-improper-base64-decoding-size-validation","tags":["third-party-advisory","Third Party Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42420","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-ccx3-fw7q-rr2r"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42420.json","tags":["advisory"]},{"url":"https://github.com/openclaw/openclaw","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-42420","title":"OpenClaw \u003c 2026.4.8 - Improper Base64 Decoding Size Validation","description":"OpenClaw before 2026.4.8 contains improper input validation in base64 decode paths that allocate memory before enforcing decoded-size limits. Attackers can exploit multiple code paths to cause memory exhaustion or denial of service through crafted base64-encoded input.","status":"published","published":"2026-04-28T18:10:11.948Z","modified":"2026-04-29T15:10:38.714Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"},{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T13:40:23.731501Z"}],"euvd":[{"id":"EUVD-2026-26123","description":"OpenClaw before 2026.4.8 contains improper input validation in base64 decode paths that allocate memory before enforcing decoded-size limits. Attackers can exploit multiple code paths to cause memory exhaustion or denial of service through crafted base64-encoded input.","status":"published","published":"2026-04-28T18:10:11Z","modified":"2026-04-29T15:10:38Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T19:05:19.922616Z"}],"ghsa":[{"id":"GHSA-ccx3-fw7q-rr2r","title":"OpenClaw: Multiple Code Paths Missing Base64 Pre-Allocation Size Checks","description":"## Impact\n\nMultiple Code Paths Missing Base64 Pre-Allocation Size Checks.\n\nSeveral base64 decode paths could allocate before enforcing decoded-size limits.\n\nOpenClaw is a user-controlled local assistant. This advisory is scoped to the OpenClaw trust model and does not assume a multi-tenant service boundary.\n\n## Affected Packages / Versions\n\n- Package: `openclaw` (npm)\n- Affected versions: `\u003c=v2026.4.2`\n- Patched versions: `2026.4.8`\n\n## Fix\n\nThe issue was fixed on `main` and is available in the patched npm version listed above. The verified fixed tree is commit `d7c3210cd6f5fdfdc1beff4c9541673e814354d5`.\n\n## Verification\n\nThe fix was re-checked against `main` before publication, including targeted regression tests for the affected security boundary.\n\n## Credits\n\nThanks @zsxsoft and @KeenSecurityLab for reporting.","status":"published","published":"2026-04-09T17:37:20Z","modified":"2026-05-06T02:41:31Z","cvss":[{"version":"4.0","score":5.1,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"},{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:40:01.917039Z"}],"nvd":[{"id":"CVE-2026-42420","description":"OpenClaw before 2026.4.8 contains improper input validation in base64 decode paths that allocate memory before enforcing decoded-size limits. Attackers can exploit multiple code paths to cause memory exhaustion or denial of service through crafted base64-encoded input.","status":"published","published":"2026-04-28T19:37:45.68Z","modified":"2026-06-17T10:47:48.483Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:12:16.252509Z"}],"osv":[{"id":"CVE-2026-42420","title":"OpenClaw \u003c 2026.4.8 - Improper Base64 Decoding Size Validation","description":"OpenClaw before 2026.4.8 contains improper input validation in base64 decode paths that allocate memory before enforcing decoded-size limits. Attackers can exploit multiple code paths to cause memory exhaustion or denial of service through crafted base64-encoded input.","status":"published","published":"2026-04-28T18:10:11.948Z","modified":"2026-10-28T02:31:02.860777896Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T15:45:04.117819Z"},{"id":"GHSA-ccx3-fw7q-rr2r","title":"OpenClaw: Multiple Code Paths Missing Base64 Pre-Allocation Size Checks","description":"## Impact\n\nMultiple Code Paths Missing Base64 Pre-Allocation Size Checks.\n\nSeveral base64 decode paths could allocate before enforcing decoded-size limits.\n\nOpenClaw is a user-controlled local assistant. This advisory is scoped to the OpenClaw trust model and does not assume a multi-tenant service boundary.\n\n## Affected Packages / Versions\n\n- Package: `openclaw` (npm)\n- Affected versions: `\u003c=v2026.4.2`\n- Patched versions: `2026.4.8`\n\n## Fix\n\nThe issue was fixed on `main` and is available in the patched npm version listed above. The verified fixed tree is commit `d7c3210cd6f5fdfdc1beff4c9541673e814354d5`.\n\n## Verification\n\nThe fix was re-checked against `main` before publication, including targeted regression tests for the affected security boundary.\n\n## Credits\n\nThanks @zsxsoft and @KeenSecurityLab for reporting.","status":"published","published":"2026-04-09T17:37:20Z","modified":"2026-05-06T02:51:11.112622Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","level":"medium"},{"version":"4.0","score":5.1,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T15:46:44.927642Z"}]}}