VulnSocial

CVE-2026-32665General(nlnetlabs / unbound)

LOWCVSS 7.5 · HIGH

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Patch nlnetlabs unbound systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

In NLnet Labs Unbound 1.22.0 up to and including 1.25.1, when downstream DNS-over-QUIC (DoQ) is enabled, the first two bidirectional streams on a new QUIC connection (stream_id 0 and 4) bypass the per-stream 'quic-size' gate entirely, and large input buffers are allocated later, after only the 2-byte length prefix has been received from the initial streams. As a result, a remote client can make Unbound exceed the configured 'quic-size' limit with low-cost input. Using only one connection and two streams, each sending a declared 65535-byte length prefix and then holding the streams open, a client can already trivially make Unbound roughly allocate double that amount. This is a remote availability issue / memory-accounting bypass in the downstream DoQ implementation that leads to denial of service for new DoQ clients. This vulnerability needs Unbound to be compiled with DoQ support ('--with-libngtcp2') and the 'quic-port' to be configured for the listening interfaces.

nlnetlabs CVEsBack to dashboard
0.5/ 10 priority

Sources & remediation

Vendor / third-party advisories
Weakness type (CWE)
CWE-1284

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

STABLE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • unbound

Threat summary

  • Patch or workaround signal is available
  • 2 mentions across 2 observed days
  • Momentum state: stable

What's happening

  • Patch or workaround mentioned in 1 signal
  • Technical details provided in 2 signals
  • General: 1 classified signal
  • Peaked 1d ago at 1 mentions (2026-07-22); latest day: 1
  • 2 total mentions across 2 days

Affected systems

Vendors
nlnetlabs
Products
unbound

Deep dive

Activity timeline2 mentions / 2d
00111Mentions · 2026-07-22: 1Mentions · 2026-07-28: 1Patch / Workaround · 2026-07-28: 1Technical Details · 2026-07-22: 1Technical Details · 2026-07-28: 107-2207-28
Signal classification2 categories
General
150.0%
Patch
150.0%
Referenced assets1 URL
By indicator
Classification over time
DateTotalLabels
2026-07-221
General1
2026-07-281
Patch1
Full discourse2 posts
  • Yasuhiro Morishita@OrangeMorishita
    General

    CVE-2026-14586 Medium DoS CVE-2026-32665 High DoS CVE-2026-40691 High DoS CVE-2026-41637 Low DoS CVE-2026-42955 Low CVE-2026-40622（幽霊ドメイン名）の追加修正 CVE-2026-44621 Medium DoS CVE-2026-44687 Low DoS（存在するドメイン名を存在しないと誤認させる） CVE-2026-44690 High キャッシュポイズニング CVE-2026-46582 Low キャッシュポイズニング CVE-2026-50045 Medium 外部へのDoS CVE-2026-50046 Medium DoS CVE-2026-50243 Medium DNSSEC検証のバイパス CVE-2026-50248 Medium DNSSEC Bogusでもゾーン転送の接続先にしてしまう CVE-2026-50251 Medium 外部からの意図的なキャッシュクリアによるDoS CVE-2026-50252 Medium UDPソースポートを外部から推測可能（キャッシュポイズニング） CVE-2026-52863 Medium DoS CVE-2026-54478 Low DNSクッキーの無力化 CVE-2026-55708 Low ローカルな名前を外部に問い合わせてしまう（情報流出） CVE-2026-55717 Medium DoS CVE-2026-55973 High DoS CVE-2026-55990 Medium DoS CVE-2026-55991 Medium DoS CVE-2026-56416 Medium DoS CVE-2026-56444 Medium DoS

    Post summary

    The bulletin simply lists CVE identifiers with severity levels and brief categories, providing no further information on exploitation, patches, or activity.

    10040503
    4.6K followersView on X
  • Open Source Security mailing list@oss_security
    Patch

    Unbound 1.25.2 fixes many CVEs https://www.openwall.com/lists/oss-security/2026/07/22/7 4 "severity: HIGH" CVE-2026-32665: Remote DNS-over-QUIC DoS CVE-2026-40691: Packet of death for DNSCrypt over TCP CVE-2026-44690: Cross-zone wildcard cache poisoning CVE-2026-55973: Stack buffer overflow + many MEDIUM and LOW

    Post summary

    Unbound 1.25.2 is released with fixes for several high‑severity CVEs, providing patch information but no evidence of active exploitation or PoC. The advisory focuses on the availability of the update.

    00030421
    4.7K followersView on X
CPE platform detail1 entries

1 of 1 entries

PartVendorProductVersionTarget SWTarget HW
Appnlnetlabsunbound---

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