by Kastro
Paper/Archive/CVE-2026-88899

CVE-2026-88899

knowns-dev knowns — knowns before 0.31.0 External Control of Agent Working Directory via x-opencode-directory Header

EPSS 0.8%CVSS 9.8
critical.is priorityof 100
41
CVSS 9.8 (CNA)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 56.9.569 × 2011.4No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

knowns versions before 0.31.0 fail to properly validate the x-opencode-directory request header in the /api/opencode proxy endpoint. Remote attackers can supply arbitrary directory paths to execute file operations outside the project root on the host system.

Affected

ProductAffectedFixed inSource
knowns< 0.31.00.31.0CNA

Scores by source

VulnCheck (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
VulnCheck (CNA)9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

advisorygithub.com/knowns-dev/knowns/security/advisories/GHSA-9h2q-r9fh-f98wwriteupgithub.com/knowns-dev/knowns/blob/v0.30.0/internal/server/server.go#L1283-L1296patchgithub.com/knowns-dev/knowns/commit/37db0561b37b48b8bd035a417d7f1da6258ae657refgithub.com/knowns-dev/knowns/releases/tag/v0.31.0writeupvulncheck.com/advisories/knowns-before-0.31.0-external-control-of-agent-working-directory-via-x-opencode-directory-header