Edgeless Systems Contrast through 1.20.0 Denial of Service via ciphertextContainer (CVE-2026-100836) | HOL Guard CVE

Medium · CVSS 5.3CVE-2026-100836

Edgeless Systems Contrast through 1.20.0 Denial of Service via ciphertextContainer

Answer in brief

CVE-2026-100836 records a Medium severity (CVSS 5.3) vulnerability in Edgeless Systems Contrast through 1.20.0 Denial of Service via ciphertextContainer. The current sources do not mark it as known exploited. The current feed maps edgelesssys/contrast (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 27, 2026Updated Sep 27, 2026Source checked Sep 27, 2026First seen by HOL Sep 27, 2026Material review Sep 27, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.3
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps edgelesssys/contrast (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
edgelesssys/contrastgeneric	>=0 <=1.20.0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for edgelesssys/contrast.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 27, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 27, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 27, 2026

Sources and claim methodology

Upstream source description

Contrast through 1.20.0 contains a panic vulnerability in the transit-engine endpoint's ciphertextContainer.UnmarshalJSON function that fails to validate decoded ciphertext length before slicing. An authenticated workload with a valid mesh certificate can trigger a runtime panic by submitting a short base64-encoded ciphertext, causing log spam and request failures without crashing the process.

Quoted source text, attributed separately from HOL analysis.