nebula-mesh: Signed-poll nonce LRU is in-memory and bounded; replay survives restart + eviction

Exploitation

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

CVSS 4.0

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

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

internal/api/pop/nonce.go:25,40,86 + internal/api/server.go:38 — the signed-poll nonce cache is an in-process LRU sized at 65,536 entries. internal/api/updates.go:31 sets pollClockSkew = 5 time.Minute as the replay window. Affected All released versions through v0.3.0 that have shipped the ADR 0004 signed-poll path. (If this is gated behind a feature flag, on a side branch, or not yet on a release tag, please flag — this advisory may not apply to the released artifact yet.) Threat model A captured signed-poll request can be replayed: 1. After any process restart — the in-memory LRU is wiped, so the original nonce becomes "unseen" again. Replay succeeds if the original timestamp is still within the 5-minute skew. 2. After forced eviction — an attacker with control of any single host can flood 65,536 nonces under their own hostid, driving the global LRU to evict the victim's recorded nonce. Replay then succeeds. Impact is bounded: a replayed poll fetches the /api/v1/agent/updates body.…

Published by the source

26 Jun 2026, 21:01 UTC

Last modified by the source

26 Jun 2026, 21:01 UTC

Source last checked

26 Oct 2026, 15:24 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-v2jf-442r-6mjh

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# Patch Next advisory brief: GHSA-v2jf-442r-6mjh

Advisory: nebula-mesh: Signed-poll nonce LRU is in-memory and bounded; replay survives restart + eviction
IDs: GHSA-v2jf-442r-6mjh
Record: https://patchnext.com/advisories/ghsa-v2jf-442r-6mjh (revision 1, source checked 26 Oct 2026, 15:24 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 2.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/juev/nebula-mesh 0.3.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/juev/nebula-mesh: affected <= 0.3.3; fixed in 0.3.4

## Suggested inspection (read-only)
- Go github.com/juev/nebula-mesh: 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/juev/nebula-mesh.
- 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://github.com/advisories/GHSA-v2jf-442r-6mjh (GitHub-reviewed advisory GHSA-v2jf-442r-6mjh lists affected ranges: Go github.com/juev/nebula-mesh >=0 <=0.3.3)

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