Vulnerability in eventsource-encoder (CVE-2026-44214)
Summary
Vulnerability in eventsource-encoder (CVE-2026-44214). Risk of unauthorized operations or information disclosure. Exploitable via event. Mitigation: upgrade to 1.0.2 or later.
Original description
The description as published by the source.
eventsource-encoder encodes events as well-formed EventSource/Server Sent Event (SSE) messages. Prior to 1.0.2, eventsource-encoder does not sanitize the event or id fields of an EventSourceMessage before serializing them. An attacker who controls either field can inject arbitrary Server-Sent Events line terminators (\n, \r, or \r\n) and thereby forge additional SSE fields or entire messages on the stream. This vulnerability is fixed in 1.0.2.
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-2026-44214 has been found in eventsource-encoder.
Attackers can target a specific entry point like event over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.8/10.
What to do: upgrade eventsource-encoder to 1.0.2 or later.
If unsure, ask your IT team or search "eventsource-encoder CVE-2026-44214" on the vendor's site.
CVE-2026-44214 (eventsource-encoder) — CWE-93 / CVSS v3 5.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: event / EventSourceMessage / data / comment
Patched: 1.0.2 — 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-93) exists in eventsource-encoder. Attackers reach the vulnerable code path via event without authentication.
Check the vendor advisory for the affected versions of eventsource-encoder. Attack surface: event / EventSourceMessage / data / comment.
Severity: Medium (CVSS 5.8/10). Risk of unauthorized operations or information disclosure.
Update to 1.0.2.
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 'eventsource-encoder' . 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
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1Identify exposure identify
grep -r 'eventsource-encoder' . | 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
eventsource-encoder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 eventsource-encoder to 1.0.2ステージング環境で 1.0.2 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
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web html.spec.whatwg.org
- web github.com