# CVE-2026-112112: Security feature bypass in BIRD

> A BGP peer can bypass IPv6 FlowSpec validation to inject unauthorized traffic filtering or redirection rules, affecting network operators using BIRD.

- **Severity:** Low 2.3 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 18 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-112112, GHSA-6jp9-p482-x6c9, UBUNTU-CVE-2026-112112

## What is CVE-2026-112112?

CVE-2026-112112 is a low-severity vulnerability in nic BIRD, published on 18 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An IPv6 FlowSpec validation bypass in the CZ.NIC BIRD Internet Routing Daemon allows an established BGP peer to inject FlowSpec rules matching destinations outside the address space authorized by the unicast-route validation procedure. With validation enabled on the receiving flow6 channel, BIRD fails to reject a destination prefix component with a nonzero offset, contrary to RFC 8956 section 5. It validates a reconstructed prefix with zero-filled skipped bits, although the original FlowSpec component can match a broader set of IPv6 addresses. Given a suitable unicast route from the peer, the rule can pass validation and, where export policy permits, be propagated to downstream peers. Downstream enforcement may cause unauthorized traffic filtering or redirection.

Weakness: CWE-1284 (Improper Validation of Specified Quantity in Input)

## Which versions are affected by CVE-2026-112112?


## How do I fix CVE-2026-112112?

No fix has been published for CVE-2026-112112 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-112112 being exploited?

There is no known exploitation of CVE-2026-112112 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-112112 and fix it if it is affected.

What it is: CVE-2026-112112 is a low-severity vulnerability in nic BIRD, published on 18 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-112112 in the wild and no public exploit code.

Affected product: nic BIRD. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-112112/ (Markdown: https://insights.sbomify.com/CVE-2026-112112/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-112112
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-112112
- OSV: https://osv.dev/vulnerability/CVE-2026-112112

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-112112/
Summaries are generated and may contain mistakes; the official description above is the record.