CVE-2026-100836: Contrast through 1.20.0 contains a panic vulnerability in the transit-engine endpoint's ciphertextContainer.UnmarshalJSON function that fails to
Affects contrastSource GCVE Database
Not known to be exploited · CVSS 5.3 Medium : upgrade to 1.20.1 when convenient.
Data as of 8 Nov 2026, 23:24 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.20.1
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:NExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 27 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CISA SSVC: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by VulnCheck
, 2 hours before disclosure
CVE published
on cve.org
, t = 0
CISA SSVC assessment
proof of concept public
, 39 hours after disclosure
In Threat Radar
record ingested
, 29 days after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA SSVC, the Metasploit, Exploit-DB and nuclei-templates index as of 9 Nov 2026.
What to do
Upgrade edgelesssys/contrast to 1.20.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
GitHubedgelesssys/contrastpkg:github/edgelesssys/contrastOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade to Contrast version 1.20.1 or later where this issue is fixed. If upgrading immediately is not possible, monitor for unusual log spam and request failures related to the transit-engine endpoint and restrict access to authenticated workloads with mesh certificates to trusted entities only.
Description
Contrast versions up to 1.20.0 contain a medium severity vulnerability (CVE-2026-100836) in the transit-engine endpoint's ciphertextContainer.UnmarshalJSON function. The flaw is due to improper validation of the length of decoded ciphertext before slicing, which can cause a runtime panic. An authenticated workload with a valid mesh certificate can exploit this by submitting a short base64-encoded ciphertext, resulting in log spam and request failures. The process does not crash, and no confidentiality or integrity impact is reported.