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CVE

CVE-2026-88899

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

CVE-2026-88899

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

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.

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
9.3
-
4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
C
H
U
0
-
C
H
U
-

Related Resources

No items found.

References

https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/88xxx/CVE-2026-88899.json, https://github.com/knowns-dev/knowns/releases/tag/v0.31.0, https://github.com/knowns-dev/knowns/security/advisories/GHSA-9h2q-r9fh-f98w, https://nvd.nist.gov/vuln/detail/CVE-2026-88899, https://www.vulncheck.com/advisories/knowns-before-0.31.0-external-control-of-agent-working-directory-via-x-opencode-directory-header, https://github.com/knowns-dev/knowns/commit/37db0561b37b48b8bd035a417d7f1da6258ae657, https://github.com/knowns-dev/knowns/blob/v0.30.0/internal/server/server.go#L1283-L1296

Severity

0

CVSS Score
0
10

Basic Information

Base CVSS
0
EPSS Probability
0.00809%
EPSS Percentile
0.55578%
Introduced Version
0
Fix Available
37db0561b37b48b8bd035a417d7f1da6258ae657

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