Vulnerability in zebrad (CVE-2026-44499)
Summary
Vulnerability in zebrad (CVE-2026-44499). Risk of unauthorized operations or information disclosure. Exploitable via inv. Mitigation: upgrade to 4.4.0 or later.
Original description
The description as published by the source.
Summary
A composite denial-of-service vulnerability in Zebra's block discovery pipeline allows an unauthenticated remote attacker to permanently halt all new block discovery on a targeted node. The attack exploits three independent weaknesses in the gossip, syncer, and download subsystems — all exercisable from a single TCP connection — to create a monotonically growing block deficit that never self-heals.
Severity
Critical — This is a Denial of Service vulnerability that requires no authentication, no special privileges, and only a single peer connection. The halt is permanent: the node will never recover without operator intervention.
Affected Versions
All Zebra versions prior to 4.4.0.
Description
Zebra discovers new blocks through two complementary paths: a gossip path (peers announce blocks via inv messages, triggering individual block downloads) and a syncer path (Zebra periodically queries peers with FindBlocks/FindHeaders to discover chains of missing blocks). Both paths must function for normal operation.
The gossip path was vulnerable because there was no per-connection rate limit on inv messages. A single connection could send enough sequential inv messages with fake block hashes to fill the entire gossip download queue in under a millisecond. The FullQueue return value was silently ignored, so legitimate block announcements from honest peers were dropped with no warning.
The syncer backup path could be degraded by responding wi…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-44499 has been found in zebrad.
Attackers can target a specific entry point like inv over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade zebrad to 4.4.0 or later.
If unsure, ask your IT team or search "zebrad CVE-2026-44499" on the vendor's site.
CVE-2026-44499 (zebrad) — CWE-770
Attack surface: inv / FindBlocks / FindHeaders / FullQueue
Patched: 4.4.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-770) exists in zebrad. Attackers reach the vulnerable code path via inv.
Check the vendor advisory for the affected versions of zebrad. Attack surface: inv / FindBlocks / FindHeaders / FullQueue.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 4.4.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'zebrad' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'zebrad' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
zebradを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade zebrad to 4.4.0ステージング環境で 4.4.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- package github.com
- web github.com
- web nvd.nist.gov
- web github.com