CVE intelligence and bounded remediation

CVE-2018-15853 — Xkbcommon Libxkbcommon security vulnerability

Medium CVSS 5.5

Endless recursion exists in xkbcomp/expr.c in xkbcommon and libxkbcommon before 0.8.1, which could be used by local attackers to crash xkbcommon users by supplying a crafted keymap file that triggers boolean negation.

Severity
Medium
CVSS
5.5 (3.0)
Published
2018-08-25
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-400

Affected products

  • xkbcommon / libxkbcommon
  • xkbcommon / xkbcommon
  • canonical / ubuntu_linux / 14.04
  • canonical / ubuntu_linux / 16.04
  • canonical / ubuntu_linux / 18.04

Matched remediation archetype

Resource exhaustion and denial of service

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
  • Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
  • Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.

Remediate safely

  • Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
  • Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
  • Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.

Authoritative sources

Complete CVE record and remediation plan

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.