Vulnerability in guzzlehttp/psr7 (CVE-2026-49214)
Summary
Vulnerability in guzzlehttp/psr7 (CVE-2026-49214). Risk of unauthorized operations or information disclosure. Exploitable via Uri. Mitigation: upgrade to 2.10.2 or later.
Original description
The description as published by the source.
guzzlehttp/psr7 is a PSR-7 HTTP message library implementation in PHP. Versions prior to 2.10.2 did not reject ASCII control characters, whitespace, or DEL in first-party URI host components. A vulnerable flow is: First, an application accepts a user-controlled URL. Second, the URL is used to construct a PSR-7 Uri or Request. Third, the host component contains CRLF or another header-unsafe character. Fourth, the host is copied into the PSR-7 Host header when no explicit Host header is provided. Finally, the request is serialized or sent by an HTTP client that does not independently reject the malformed host. In that flow, an attacker can cause the serialized request to contain additional attacker-controlled header lines. For example, a host containing "\r\nX-Injected: yes" can cause the generated Host header to span multiple HTTP header lines. Applications are affected when they use user-controlled URLs for outbound HTTP requests, URL forwarding, proxying, crawling, webhook delivery, or similar request-dispatch flows. In deployments involving HTTP/1.1 connection reuse, proxies, gateways, or load balancers, this malformed request may also contribute to request smuggling or cache poisoning, depending on how downstream components parse the request. The issue is patched in 2.10.2 and later. 1.x is end-of-life and will not receive a patch. As a workaround, validate and reject all untrusted URI strings before constructing PSR-7 Uri or Request instances. Reject i…
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-2026-49214 has been found in guzzlehttp/psr7.
Attackers can target a specific entry point like Uri over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: upgrade guzzlehttp/psr7 to 2.10.2 or later.
If unsure, ask your IT team or search "guzzlehttp/psr7 CVE-2026-49214" on the vendor's site.
CVE-2026-49214 (guzzlehttp/psr7) — CWE-20 / CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: Uri / Request / Host
Patched: 2.10.2 — 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-20) exists in guzzlehttp/psr7. Attackers reach the vulnerable code path via Uri without authentication.
Check the vendor advisory for the affected versions of guzzlehttp/psr7. Attack surface: Uri / Request / Host.
Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure.
Update to 2.10.2.
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 'guzzlehttp/psr7' . 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 'guzzlehttp/psr7' . | 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
guzzlehttp/psr7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 guzzlehttp/psr7 to 2.10.2ステージング環境で 2.10.2 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。
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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-2026-49214 php-guzzlehttp-psr7
- Ubuntu UBUNTU-CVE-2026-49214 php-guzzlehttp-psr7
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com
- web github.com