CVE-2023-27560

phpseclib Infinite Loop vulnerability

7.5 HighFix available

Math/PrimeField.php in phpseclib 3.x before 3.0.19 has an infinite loop with composite primefields.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

0.81%Down 0.1 points since Mar 3, 2023

What each source reports

NVD Score used 7.5

Math/PrimeField.php in phpseclib 3.x before 3.0.19 has an infinite loop with composite primefields.

Record: CVE-2023-27560
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-835
Updated: 2026-11-02

CVE List 7.5

Math/PrimeField.php in phpseclib 3.x before 3.0.19 has an infinite loop with composite primefields.

Record: CVE-2023-27560
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-835
Updated: 2026-11-02

EUVDEUVD-2023-1036 7.5

Math/PrimeField.php in phpseclib 3.x before 3.0.19 has an infinite loop with composite primefields.

Record: EUVD-2023-1036
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

GitHub AdvisoriesGHSA-hm7p-r324-hhf3 7.5

phpseclib Infinite Loop vulnerability

Math/PrimeField.php in phpseclib has an infinite loop with composite primefields. This vulnerability was introduced in version 3.0.0, and has been patched in 3.0.19. The CVE for this issue originally identified the the vulnerable version as 2.x, however, the vulnerable functionality was not introduced until version 3.

Record: GHSA-hm7p-r324-hhf3
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-835
Updated: 2026-11-02

OSV 7.5

Math/PrimeField.php in phpseclib 3.x before 3.0.19 has an infinite loop with composite primefields.

Record: CVE-2023-27560
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVDEBIAN-CVE-2023-27560 7.5

Math/PrimeField.php in phpseclib 3.x before 3.0.19 has an infinite loop with composite primefields.

Record: DEBIAN-CVE-2023-27560
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVGHSA-hm7p-r324-hhf3 7.5

phpseclib Infinite Loop vulnerability

Record: GHSA-hm7p-r324-hhf3
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-835
Updated: 2026-11-02

OSVUBUNTU-CVE-2023-27560 7.5

Math/PrimeField.php in phpseclib 3.x before 3.0.19 has an infinite loop with composite primefields.

Record: UBUNTU-CVE-2023-27560
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

Affected products

phpseclib

Affected packages

Affected packages
Package	Affected	Fixed
`phpseclib/phpseclib` Packagist	3.0.0 up to 3.0.19	3.0.19
`php-phpseclib3` Debian:12	before 3.0.19-1	3.0.19-1
`php-phpseclib3` Debian:13	before 3.0.19-1	3.0.19-1
`php-phpseclib3` Debian:14	before 3.0.19-1	3.0.19-1
`phpseclib/phpseclib` Packagist	3.0.0 up to 3.0.19, plus listed versions 3.0.13.0.103.0.113.0.123.0.13 Show 13 moreShow less 3.0.143.0.153.0.163.0.173.0.183.0.23.0.33.0.43.0.53.0.63.0.73.0.83.0.9	3.0.19
`ldap-account-manager` Ubuntu:16.04:LTS	All versions, plus listed versions 4.9-15.1-15.2-15.2-1ubuntu1	None known
`php-phpseclib` Ubuntu:Pro:16.04:LTS	All versions, plus listed versions 2.0.1-12.0.1-1build12.0.1-1ubuntu0.1~esm12.0.1-1ubuntu0.1~esm2	None known
`ldap-account-manager` Ubuntu:18.04:LTS	All versions, plus listed versions 5.7-16.1-16.2-1	None known
`php-phpseclib` Ubuntu:Pro:18.04:LTS	All versions, plus listed versions 2.0.6-12.0.7-12.0.9-12.0.9-1ubuntu0.1~esm22.0.9-1ubuntu0.1~esm3	None known
`ldap-account-manager` Ubuntu:20.04:LTS	All versions, plus listed versions 6.7-1	None known

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Affected packages
Package	Affected	Fixed
`php-phpseclib` Ubuntu:Pro:20.04:LTS	All versions, plus listed versions 2.0.21-22.0.23-22.0.23-2ubuntu0.1~esm22.0.23-2ubuntu0.1~esm3	None known
`ldap-account-manager` Ubuntu:22.04:LTS	All versions, plus listed versions 7.5-17.7-1	None known
`php-phpseclib` Ubuntu:Pro:22.04:LTS	All versions, plus listed versions 2.0.30-2ubuntu12.0.34-12.0.35-12.0.36-12.0.36-1ubuntu0.1~esm22.0.36-1ubuntu0.1~esm3	None known
`php-phpseclib3` Ubuntu:Pro:22.04:LTS	All versions, plus listed versions 3.0.9-13.0.10-13.0.12-23.0.13-13.0.13-1ubuntu0.1~esm1	None known
`ldap-account-manager` Ubuntu:24.04:LTS	All versions, plus listed versions 8.3-18.5-1	None known
`php-phpseclib3` Ubuntu:24.04:LTS	All versions, plus listed versions 3.0.21-23.0.33-13.0.34-13.0.35-13.0.37-1	None known
`php-phpseclib` Ubuntu:Pro:24.04:LTS	All versions, plus listed versions 2.0.44-12.0.45-12.0.46-12.0.47-12.0.47-1ubuntu0.1~esm1	None known
`ldap-account-manager` Ubuntu:25.10	All versions, plus listed versions 9.0-1	None known
`php-phpseclib` Ubuntu:25.10	All versions, plus listed versions 2.0.48-3	None known
`php-phpseclib3` Ubuntu:25.10	All versions, plus listed versions 3.0.43-2	None known
`php-phpseclib` Ubuntu:26.10	All versions, plus listed versions 2.0.51-12.0.54-12.0.55-1	None known
`php-phpseclib3` Ubuntu:26.10	All versions, plus listed versions 3.0.49-1ubuntu13.0.57-1	None known
`ldap-account-manager` Ubuntu:26.04:LTS	All versions, plus listed versions 9.0-19.0-1build1	None known
`php-phpseclib3` Ubuntu:26.04:LTS	All versions, plus listed versions 3.0.43-23.0.44-13.0.47-13.0.49-13.0.49-1ubuntu1	None known
`php-phpseclib` Ubuntu:Pro:26.04:LTS	All versions, plus listed versions 2.0.48-32.0.49-12.0.51-12.0.51-1ubuntu0.1~esm1	None known

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2023-27560 is a high vulnerability (CVSS 7.5) in Phpseclib, published March 3, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.81%, the 57th percentile. Fixed in phpseclib/phpseclib 3.0.19.

References

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