CVE-2023-49316: Phpseclib/phpseclib Phpseclib Needs Guardrails On Large Vulnerability

HIGH
Advisory Identifier: GHSA-2f25-pfq3-c7h8
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CVSS 7.5
CWE-834 CWE-400
Published
Advisory Summary

CVE-2023-49316 is a HIGH (CVSS 7.5) phpseclib needs guardrails on large vulnerability (CWE-834: Excessive Iteration) affecting Phpseclib/phpseclib libraries in the Packagist ecosystem. The issue involves phpseclib needs guardrails on large binaryfield integers. Remediation is available by upgrading affected packages to version 3.0.34.

CVE-2023-49316 at a Glance

CVE Identifier CVE-2023-49316
GHSA Identifier GHSA-2f25-pfq3-c7h8
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-834: Excessive Iteration
Affected Product Phpseclib/phpseclib
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2023-49316

To remediate this vulnerability, upgrade all affected Phpseclib/phpseclib dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

phpseclib/phpseclib fixed: 3.0.34 
Upgrade phpseclib/phpseclib to 3.0.34
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for phpseclib/phpseclib

How to Check if You Are Affected

To determine whether your application is affected by CVE-2023-49316, inspect your project dependencies for Phpseclib/phpseclib:

inspect dependencies for phpseclib/phpseclib

Analyze the terminal output to locate any version of Phpseclib/phpseclib in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.0.34), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-834: Excessive Iteration, where the product performs an iteration or loop without sufficiently limiting the number of times that the loop is executed. In Phpseclib/phpseclib, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact Anyone loading untrusted ASN1 files (eg. X509 certificates, RSA PKCS8 private or public keys, etc) ### Patches https://github.com/phpseclib/phpseclib/commit/964d78101a70305df33f442f5490f0adb3b7e77f ### Workarounds No. ### References https://github.com/phpseclib/phpseclib/commit/964d78101a70305df33f442f5490f0adb3b7e77f https://www.usenix.org/system/files/usenixsecurity25-shi-bing.pdf

CVE-2023-49316 Affected Phpseclib/phpseclib Versions

1 component(s)
Fixed Versions:
3.0.34
Product / Package Ecosystem Affected Versions Fixed Version
phpseclib/phpseclib
 Packagist
≥ 3.0.0
< 3.0.34
3.0.34

References

GitHub Advisory / Wiki ADVISORY
https://github.com/phpseclib/phpseclib/security/advisories/GHSA-2f25-pfq3-c7h8
NVD — CVE-2023-49316 NVD
https://nvd.nist.gov/vuln/detail/CVE-2023-49316
Security Fix Commit FIX COMMIT
https://github.com/phpseclib/phpseclib/commit/964d78101a70305df33f442f5490f0adb3b7e77f
Phpseclib/phpseclib Source Repository REPOSITORY
https://github.com/FriendsOfPHP/security-advisories/blob/master/phpseclib/phpseclib/CVE-2023-49316.yaml
Phpseclib/phpseclib Source Repository REPOSITORY
https://github.com/phpseclib/phpseclib
Phpseclib/phpseclib Release RELEASE
https://github.com/phpseclib/phpseclib/releases/tag/3.0.34

Frequently Asked Questions

What is CVE-2023-49316?
CVE-2023-49316 is a security vulnerability in Phpseclib/phpseclib involving Phpseclib needs guardrails on large binaryfield integers under CWE-834: Excessive Iteration.
Which Phpseclib/phpseclib versions are affected?
Affected versions include releases prior to 3.0.34 across affected packages: phpseclib/phpseclib.
What version fixes CVE-2023-49316?
Upgrading to 3.0.34 (or the latest patched release for your respective branch) resolves the vulnerability.
Is phpseclib/phpseclib affected?
Yes, phpseclib/phpseclib is affected in releases prior to 3.0.34. Upgrade your dependency to 3.0.34 or later.
What is the CVSS score of CVE-2023-49316?
CVE-2023-49316 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2023-49316?
CVE-2023-49316 is classified under CWE-834: Excessive Iteration (The product performs an iteration or loop without sufficiently limiting the number of times that the loop is executed.).
How can I check Packagist dependencies for CVE-2023-49316?
Run the dependency tree command: 'inspect dependencies for phpseclib/phpseclib'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-2f25-pfq3-c7h8",
  "modified" : "2026-05-08T23:06:50Z",
  "published" : "2026-05-08T23:06:50Z",
  "aliases" : [ "CVE-2023-49316" ],
  "summary" : "Phpseclib needs guardrails on large binaryfield integers",
  "details" : "### Impact\nAnyone loading untrusted ASN1 files (eg. X509 certificates, RSA PKCS8 private or public keys, etc)\n\n### Patches\nhttps://github.com/phpseclib/phpseclib/commit/964d78101a70305df33f442f5490f0adb3b7e77f\n\n### Workarounds\nNo.\n\n### References\nhttps://github.com/phpseclib/phpseclib/commit/964d78101a70305df33f442f5490f0adb3b7e77f\nhttps://www.usenix.org/system/files/usenixsecurity25-shi-bing.pdf",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "phpseclib/phpseclib"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.0.0"
      }, {
        "fixed" : "3.0.34"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/phpseclib/phpseclib/security/advisories/GHSA-2f25-pfq3-c7h8"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-49316"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/phpseclib/phpseclib/commit/964d78101a70305df33f442f5490f0adb3b7e77f"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FriendsOfPHP/security-advisories/blob/master/phpseclib/phpseclib/CVE-2023-49316.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/phpseclib/phpseclib"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/phpseclib/phpseclib/releases/tag/3.0.34"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-400", "CWE-834" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-08T23:06:50Z",
    "nvd_published_at" : null
  }
}