# CVE-2026-53499: FORT-validator Vulnerable to RRDP Shared Snapshot Cache Poisoning


- **Severity:** High 7.2 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:H/SA:H`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 21 Aug 2026
- **Updated:** 25 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-53499, GHSA-qfm3-577x-rh54, UBUNTU-CVE-2026-53499

## What is CVE-2026-53499?

CVE-2026-53499 is a high-severity vulnerability in NICMx FORT-validator, published on 21 Aug 2026. 

### Official description

FORT Validator is a Resource Public Key Infrastructure (RPKI) relying-party validator that produces validated route-origin data. FORT Validator versions through 1.6.7 contain an origin-validation error in their RRDP processing: a delegated CA under the same Trust Anchor Locator (TAL) can reference a victim CA’s public RRDP notification and snapshot URLs, causing FORT’s URL-based download cache to report success after deleting the victim’s local snapshot. Following a routine victim publication, this can silently remove the victim’s VRPs and other signed objects from FORT’s output, potentially enabling route hijacking or loss of reachability. Version 1.6.8 contains a patch that rejects cross-origin RRDP snapshot and delta URLs; as a workaround, administrators can disable HTTP/RRDP with  --http.enabled=false  while keeping rsync enabled, although this can leave data unavailable or stale where rsync is not supported.

Weakness: CWE-346 (Origin Validation Error)

## Which versions are affected by CVE-2026-53499?


## How do I fix CVE-2026-53499?

Upgrade to a fixed version.

## Is CVE-2026-53499 being exploited?

There is no known exploitation of CVE-2026-53499 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53499 and fix it if it is affected.

What it is: CVE-2026-53499 is a high-severity vulnerability in NICMx FORT-validator, published on 21 Aug 2026. 
Exploitation: There is no known exploitation of CVE-2026-53499 in the wild and no public exploit code.

Affected product: NICMx FORT-validator. 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-2026-53499/ (Markdown: https://insights.sbomify.com/CVE-2026-53499/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53499
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53499
- OSV: https://osv.dev/vulnerability/CVE-2026-53499

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53499/
Summaries are generated and may contain mistakes; the official description above is the record.