# CVE-2026-100835: Contrast before 1.16.0 Remote Attestation Relay Attack

> Attackers can bypass remote attestation by relaying valid reports from compromised hardware, impersonating trusted components in Contrast's attested TLS.

- **Severity:** Critical 9.1 (`CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Sep 2026
- **Updated:** 30 Sep 2026
- **Also known as:** GHSA-hjgc-jc5v-fw7h, GHSA-jw33-f4wc-8736

## What is CVE-2026-100835?

CVE-2026-100835 is a critical vulnerability in edgelesssys contrast, published on 27 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Contrast before 1.16.0 is susceptible to remote attestation relay attacks. Contrast accepted any TEE attestation report that verified correctly and contained the expected firmware patch levels and software measurements, regardless of which machine produced it, so attestation was not bound to specific, physically trusted hardware. An attacker who can both intercept network traffic between the CLI and the Coordinator (or between the Coordinator and an attested component) and forge reports or extract secrets from any single TEE machine under their physical control can relay such a report to impersonate a Contrast Coordinator or a Contrast workload, defeating identity verification in Contrast's attested TLS (aTLS).

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2026-100835?


## How do I fix CVE-2026-100835?

No fix has been published for CVE-2026-100835 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-100835 being exploited?

There is no known exploitation of CVE-2026-100835 in the wild and no public exploit code.

Public exploit code:

- CVE-2026-100835 PoC: Edgeless Contrast <1.16.0 remote attestation relay (aTLS / CWE-295). Manifest audit (AllowedChipIDs/AllowedPIIDs), version & coordinator probe. https://pocbit.org/pocs/cve-2026-100835 (github_poc): https://github.com/murrez/CVE-2026-100835

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-100835 and fix it if it is affected.

What it is: CVE-2026-100835 is a critical vulnerability in edgelesssys contrast, published on 27 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-100835 in the wild and no public exploit code.

Affected product: edgelesssys contrast. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-100835/ (Markdown: https://insights.sbomify.com/CVE-2026-100835/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-100835
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-100835
- OSV: https://osv.dev/vulnerability/CVE-2026-100835

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-100835/
Summaries are generated and may contain mistakes; the official description above is the record.