CVE-2026-92697
FastNetMon: NetFlow v9 unbounded strlen() on interface-description field causes remote out-of-bounds read
What happened?
FastNetMon is a high-performance DDoS detector and sensor. In version 1.2.9 and earlier, the NetFlow v9 collector calls strlen() on an attacker-controlled interface-description field without bounding the scan to the field’s declared length. Although fields longer than 128 bytes are excluded from this operation, an accepted field without a null terminator can cause reads beyond the field and packet buffer. An unauthenticated remote attacker who can send crafted UDP packets to the collector can trigger an out-of-bounds read and potentially crash the process, causing denial of service. No fixed release is available as of this review.
Affected software and versions
| Software | Version information | Fixed version |
|---|---|---|
| fastnetmonpavel-odintsov | affected: <= 1.2.9 | See vendor advisory |
Version information comes from the source record and can include unaffected products and exceptions. Distribution packages may contain backported fixes: an older upstream version alone does not prove a server is affected.
Is it being exploited?
This CVE was not listed in the CISA catalogue at our last retrieval. This does not establish that exploitation is absent.
How to respond
- Confirm the product, installed package version, and any configuration requirements in the vendor advisory.
- Follow the vendor’s remediation or workaround guidance in the references below. Structured fixed-version data is unavailable here; the publisher’s description may include a fix or workaround.
- Restart affected services if required, then verify the running version. Known exploitation may warrant investigation as well as patching.