Vulnerability in guzzlehttp/guzzle-services (CVE-2026-53723)
Summary
Vulnerability in guzzlehttp/guzzle-services (CVE-2026-53723). Risk of unauthorized operations or information disclosure. Exploitable via additionalParameters. Mitigation: upgrade to 1.5.4 or later.
Original description
The description as published by the source.
Guzzle Services provides an implementation of the Guzzle Command library that uses Guzzle service descriptions to describe web services, serialize requests, and parse responses into easy to use model structures. Versions prior ro 1.5.4 do not safely serialize scalar XML element values containing the CDATA terminator ]]>. The XML request serializer writes values containing <, >, or & with XMLWriter::writeCData($value). If attacker-controlled input contains ]]>, the CDATA section closes early and the remainder is interpreted as XML markup. This is an outgoing request-body integrity issue, not a response parsing issue. The attacker does not need to control the service description or schema. Users are affected when all of the following are true: the application uses guzzlehttp/guzzle-services to serialize outgoing requests; a request parameter or additionalParameters schema uses location: xml; the value is serialized as XML element text, not an XML attribute; the value can contain attacker-controlled, user-controlled, tenant-controlled, or otherwise untrusted input; the value is not constrained by a safe enum, pattern, or custom filter that excludes ]]>; and the downstream service parses the generated XML structurally and may act on unexpected, duplicated, or injected elements. Applications that serialize untrusted input into location: xml request parameters can emit XML containing attacker-controlled elements outside the intended text node. Depending on…
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-2026-53723 has been found in guzzlehttp/guzzle-services.
Attackers can target a specific entry point like additionalParameters over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.8/10.
What to do: upgrade guzzlehttp/guzzle-services to 1.5.4 or later.
If unsure, ask your IT team or search "guzzlehttp/guzzle-services CVE-2026-53723" on the vendor's site.
CVE-2026-53723 (guzzlehttp/guzzle-services) — CWE-20 / CVSS v3 5.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: additionalParameters / enum / pattern / DisplayName
Patched: 1.5.4 — 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/guzzle-services. Attackers reach the vulnerable code path via additionalParameters without authentication.
Check the vendor advisory for the affected versions of guzzlehttp/guzzle-services. Attack surface: additionalParameters / enum / pattern / DisplayName.
Severity: Medium (CVSS 5.8/10). Risk of unauthorized operations or information disclosure.
Update to 1.5.4.
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/guzzle-services' . 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/guzzle-services' . | 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/guzzle-services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/guzzle-services to 1.5.4ステージング環境で 1.5.4 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
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com
- web github.com