Vulnerability in github.com/junegunn/fzf (CVE-2026-53433)
Summary
Vulnerability in github.com/junegunn/fzf (CVE-2026-53433). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 0.73.1 or later.
Original description
The description as published by the source.
fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the --listen mode due to inefficient HTTP body processing using repeated string concatenation, resulting in quadratic time complexity (O(n²)). A crafted POST request with many small segments can trigger excessive CPU usage during request handling.This allows a single malicious request to monopolize the single‑threaded HTTP server, blocking all other clients and resulting in denial of service.
This issue was fixed in version 0.73.1.
Source: GitHub Security Advisories (Global) 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-2026-53433 has been found in github.com/junegunn/fzf.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade github.com/junegunn/fzf to 0.73.1 or later.
If unsure, ask your IT team or search "github.com/junegunn/fzf CVE-2026-53433" on the vendor's site.
CVE-2026-53433 (github.com/junegunn/fzf) — CWE-407 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 0.73.1 — 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-407) exists in github.com/junegunn/fzf.
Check the vendor advisory for the affected versions of github.com/junegunn/fzf.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to 0.73.1.
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 'github.com/junegunn/fzf' . 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 'github.com/junegunn/fzf' . | 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
github.com/junegunn/fzf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 github.com/junegunn/fzf to 0.73.1ステージング環境で 0.73.1 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
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-53433 fzf
- Ubuntu UBUNTU-CVE-2026-53433 fzf
References
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com
- web cert.pl
- web github.com