Vulnerability in Xml (CVE-2026-18568)
Summary
Vulnerability in Xml (CVE-2026-18568). Data can be tampered with by attackers. Exploitable via next.
Original description
The description as published by the source.
XML::Sig versions from 0.29 before 0.72 for Perl allow signature verification bypass because verify returns true when every signature was skipped before any cryptographic check.
verify in lib/XML/Sig.pm counts the //dsig:Signature elements into $numsigs and iterates over them, but two paths reach next before any digest or key check runs: a SignedInfo/Reference/@URI that resolves to no element while $numsigs is greater than 1, and, when id_attr is set, a reference that does not match the requested ID. The loop records nothing about what it checked, so when every signature takes one of those paths control reaches the unconditional return 1 that ends verify. Two Signature elements whose Reference URI names an ID that no element carries is enough, as is one such element combined with id_attr.
Any caller that passes untrusted XML to verify can receive a true return for a document in which no digest and no signature value was checked; a cert or cert_text trust anchor does not change this, because no key check runs. Versions up to 0.28 use an XML::XPath based verify that has no such skip and are not affected.
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-2026-18568 has been found in Xml.
Attackers can target a specific entry point like next over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 7.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Xml CVE-2026-18568" on the vendor's site.
CVE-2026-18568 (Xml) — CWE-347 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: next / id_attr / Signature / cert
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-347) exists in Xml. Attackers reach the vulnerable code path via next without authentication.
Check the vendor advisory for the affected versions of Xml. Attack surface: next / id_attr / Signature / cert.
Severity: High (CVSS 7.5/10). Data can be tampered with by attackers.
Update to the patched release per vendor advisory.
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 'Xml' . 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 'Xml' . | 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
Xmlを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-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。
References
- patch github.com
- web nvd.nist.gov
- web metacpan.org
- web cve.org
- web github.com