CVE-2026-100838

highpriority · track · 32EPSS 0.002 · 13 %ileUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.22% (13th) EPSS
CVSS 8.1 · high
Is it mine?
1 products
Check your exposure
Who says so?
1 sources
osv

EPSS · scored 2026-10-27

Contrast is a confidential-computing runtime for Kubernetes. In versions before 1.19.1, the Kata agent policies generated by the Contrast CLI contained a flaw in the CopyFile verification that allowed arbitrary writes to the guest root filesystem. A malicious process on the untrusted host able to connect to the Kata agent VSOCK could issue a series of CopyFile requests to overwrite security-critical files in the guest or trick the workload into disclosing sensitive data, effectively amounting to a full guest takeover. Users unable to upgrade can apply an equivalent rego policy fix passed to 'contrast generate --policy'.

01

cvss

Technical severity, 0–10. One row per scoring source.

8.6
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.2–8.6

v3.18.1highCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Nprimary · disclosure@vulncheck.comexploitability 2.8 · impact 5.2
v3.18.1highCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Nsecondary · OSV
v4.08.6highCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/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:Xsecondary · disclosure@vulncheck.com
v4.06.2mediumCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/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:Xsecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-59USCWE-59US
04

affected products (1)

Products and version ranges known to be affected.

05

advisories (2)

Vendor and ecosystem advisories describing this.

  • GHSA-rh99-wc69-c255Contras Affected by CopyFile Policy Subversion via Symlinks2026-04-30ghsa · osvUS

    ### Impact The [Kata agent policies](https://docs.edgeless.systems/contrast/architecture/components/policies) generated by the Contrast CLI had an issue in the `CopyFile` verification, which allowed arbitrary writes to the guest root filesytem. A malicious process on the host with the capability to connect to the Kata agent VSOCK could connect to the agent and issue a series of `CopyFile` requests to overwrite security-critical files or trick the workload into disclosing sensitive data, which effectively amounts to a full guest takeover. ### Patches This issue has been patched in Contrast v1.19.1. Note that this fix does not change the fact that host-provided content is generally not trustworthy, as documented. ### Workarounds If upgrading is not possible, users can implement the fix in rego and pass it to `contrast generate --policy`. The rego-only fix is a bit trickier than the patch, because the data to check is binary. See the references for details. ### Resources * Upstream GHSA: https://github.com/kata-containers/kata-containers/security/advisories/GHSA-q49m-57vm-c8cc * Alternative policy-only fix: https://gist.github.com/burgerdev/304dd0ab0fff1665b7c27e18a30cf96e

  • GO-2026-5624Contras Affected by CopyFile Policy Subversion via Symlinks in github.com/edgelesssys/contrast2026-06-25vendor · osvUS

    Contras Affected by CopyFile Policy Subversion via Symlinks in github.com/edgelesssys/contrast

06

also known as (2)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

osvNVDCVE.orgMITRE
published 2026-09-27modified 2026-10-08
08

references (2) nvd

External citations — patches, advisories, analysis.

scry

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