libp2p-rendezvous: Unbounded rendezvous DISCOVER cookies enable remote memory exhaustion

Exploitation

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

CVSS

8.2 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

EPSS

• CVE-2026-35457: 0.29% estimated exploitation activity in the next 30 days; percentile 21.10 (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 rendezvous server stores pagination cookies without bounds. An unauthenticated peer can repeatedly issue DISCOVER requests and force unbounded memory growth. Details Pagination state is stored in: On Message::Discover: There is no upper bound or eviction policy, so repeated DISCOVER requests grow this map indefinitely. PoC A reproduction test and minimal harness will be provided in a private fork in a follow-up comment. Impact Remote state amplification leading to memory exhaustion. Properties: - etwork reachable - no authentication required - low attack complexity - protocol-compliant traffic Impacts rendezvous nodes exposed to untrusted peers. --- Possible Fixes 1. Global cap + eviction Bound cookie storage (MAXCOOKIESTRACKED) with FIFO/expiry aware eviction. Tradeoff: attacker can churn cookies and evict legitimate pagination state. 2. Stateless cookies Encode pagination state in authenticated cookies instead of storing server-side state. Tradeoff: more complex…

Published by the source

4 Apr 2026, 06:34 UTC

Last modified by the source

7 Apr 2026, 19:59 UTC

Source last checked

26 Oct 2026, 15:42 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-v5hw-cv9c-rpg7

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# Patch Next advisory brief: CVE-2026-35457

Advisory: libp2p-rendezvous: Unbounded rendezvous DISCOVER cookies enable remote memory exhaustion
IDs: CVE-2026-35457, GHSA-v5hw-cv9c-rpg7
Record: https://patchnext.com/advisories/cve-2026-35457 (revision 1, source checked 26 Oct 2026, 15:42 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: libp2p-rendezvous 0.17.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io libp2p-rendezvous: affected < 0.17.1; fixed in 0.17.1

## Suggested inspection (read-only)
- crates.io libp2p-rendezvous: 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 libp2p-rendezvous.
- 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-v5hw-cv9c-rpg7 (GitHub-reviewed advisory GHSA-v5hw-cv9c-rpg7 lists affected ranges: crates.io libp2p-rendezvous >=0 <0.17.1)

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