# CVE-2018-15857: libxkbcommon0: An invalid free in ExprAppendMultiKeysymList in xkbcomp/ast-build.c in xkbcommon before 0.8.1 could be used by local...

CVE-2018-15857 is fixed in 2 products on 1 platform, first by libxkbcommon-x11-0 0.8.0-1ubuntu0.1, released August 24, 2018. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2018-15857
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0045
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 24, 2018

## Description

An invalid free in ExprAppendMultiKeysymList in xkbcomp/ast-build.c in xkbcommon before 0.8.1 could be used by local attackers to crash xkbcommon keymap parsers or possibly have unspecified other impact by supplying a crafted keymap file.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libxkbcommon-x11-0 Ubuntu 18.04.6 LTS (bionic) | 0.8.0-1ubuntu0.1 | [libxkbcommon-x11-0 0.8.0-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libxkbcommon-x11-0-0.8.0-1ubuntu0.1.md) | Aug 24, 2018 |
| Linux | libxkbcommon0 Ubuntu 18.04.6 LTS (bionic) | 0.8.0-1ubuntu0.1 | [libxkbcommon0 0.8.0-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libxkbcommon0-0.8.0-1ubuntu0.1.md) | Aug 24, 2018 |

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