GoPacket's sFlow ExtendedGatewayFlow decoder: unbounded attacker-controlled allocation (104-byte UDP datagram -> up to 16 GiB make) -> unauthenticated remote DoS

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.9 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-54332: 0.79% estimated exploitation activity in the next 30 days; percentile 56.32 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The sFlow ExtendedGatewayFlow record decoder in github.com/gopacket/gopacket allocates a slice with make([]uint32, n) where n is an attacker-controlled 32-bit wire field that has no upper bound. Because the allocation happens before the read loop that would consume the corresponding bytes, a single small UDP datagram can force a multi-gigabyte allocation. A 104-byte sFlow datagram can request up to 16 GiB and OOM-kill any service that parses sFlow with gopacket. This is an unauthenticated remote denial of service (CWE-770). Root cause (file:line @ v1.6.0) Two sinks in layers/sflow.go, both in the ExtendedGatewayFlow (record type 1003) decode path: 1. layers/sflow.go:1306 in decodeExtendedGatewayFlowRecord: 2. layers/sflow.go:1276 in decodePath (a helper called from the same record decoder): In both cases the make is executed before the loop that reads the element bytes, so the allocation size is fully determined by the attacker-supplied count field and is never checked…

Published by the source

28 Jul 2026, 16:17 UTC

Last modified by the source

18 Aug 2026, 15:00 UTC

Source last checked

26 Oct 2026, 15:27 UTC

1. Revision 4 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-g6v3-7xmc-w563

2. Revision 3 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GO-2026-6122

4. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-g6v3-7xmc-w563

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# Patch Next advisory brief: CVE-2026-54332

Advisory: GoPacket's sFlow ExtendedGatewayFlow decoder: unbounded attacker-controlled allocation (104-byte UDP datagram -> up to 16 GiB make) -> unauthenticated remote DoS
IDs: CVE-2026-54332, GHSA-g6v3-7xmc-w563
Record: https://patchnext.com/advisories/cve-2026-54332 (revision 4, source checked 26 Oct 2026, 15:27 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/gopacket/gopacket 1.6.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/gopacket/gopacket: affected <= 1.6.0; fixed in 1.6.1

## Suggested inspection (read-only)
- Go github.com/gopacket/gopacket: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/gopacket/gopacket.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-g6v3-7xmc-w563 (OSV record GHSA-g6v3-7xmc-w563 lists affected ranges: Go github.com/gopacket/gopacket >=0 <1.6.1 (fixed))
- Verified: https://osv.dev/vulnerability/GO-2026-6122 (OSV record GO-2026-6122 lists affected ranges: Go github.com/gopacket/gopacket >=0 <1.6.1 (fixed))
- Verified: https://github.com/advisories/GHSA-g6v3-7xmc-w563 (GitHub-reviewed advisory GHSA-g6v3-7xmc-w563 lists affected ranges: Go github.com/gopacket/gopacket >=0 <=1.6.0)

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