Vulnerability in phalcon/cphalcon (CVE-2026-54736)
Summary
Vulnerability in phalcon/cphalcon (CVE-2026-54736). Risk of unauthorized operations or information disclosure. Exploitable via useSigning. Mitigation: upgrade to 5.14.1 or later.
Original description
The description as published by the source.
Phalcon is a high-performance, full-stack PHP framework. Prior to 5.14.1, Phalcon\Encryption\Crypt::decrypt compares the attacker-supplied HMAC tag against the freshly computed HMAC using PHP/Zephir identity comparison, which lowers to a byte-wise comparison that returns early on the first differing byte. This observable timing discrepancy can allow an attacker to recover a valid tag byte-by-byte and attach it to a chosen IV and ciphertext so that decrypt() accepts tampered encrypted content as authentic. This issue is fixed in version 5.14.1.
Source: NIST National Vulnerability Database 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-2026-54736 has been found in phalcon/cphalcon.
Attackers can target a specific entry point like useSigning over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade phalcon/cphalcon to 5.14.1 or later.
If unsure, ask your IT team or search "phalcon/cphalcon CVE-2026-54736" on the vendor's site.
CVE-2026-54736 (phalcon/cphalcon) — CWE-208
Attack surface: useSigning / memcmp / zephir_hash_equals / ZEPHIR_IS_IDENTICAL
Patched: 5.14.1 — 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-208) exists in phalcon/cphalcon. Attackers reach the vulnerable code path via useSigning.
Check the vendor advisory for the affected versions of phalcon/cphalcon. Attack surface: useSigning / memcmp / zephir_hash_equals / ZEPHIR_IS_IDENTICAL.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 5.14.1.
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 'phalcon/cphalcon' . 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 'phalcon/cphalcon' . | 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
phalcon/cphalcon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 phalcon/cphalcon to 5.14.1ステージング環境で 5.14.1 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
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- patch github.com
- patch github.com
- report github.com
- web github.com
- web github.com