VulnerabilityPublished 13 Mar 2026Updated 16 Mar 2026

CVE-2026-32600: simplesamlphp xml-security · Improper Validation of Integrity Check Value

Affects simplesamlphp xml-securitySource CVE Database V5

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Not known to be exploited · CVSS 8.2 High : upgrade to 2.3.1 or 1.13.9 soon.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

8.2High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.3.1, 1.13.9

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 13 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade xml-security to 2.3.1 or 1.13.9; simplesamlphp/xml-security to 1.13.9.

Affected software

Product	Affected	Fixed in
simplesamlphpxml-security	Affected >=2.0.0 <2.3.1	Fixed in 2.3.1
simplesamlphpxml-security	Affected <1.13.9	Fixed in 1.13.9
GitHubsimplesamlphp/xml-security`pkg:github/simplesamlphp/xml-security`Other threats	Affected <1.13.9	Fixed in 1.13.9

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Organizations should immediately upgrade the simplesamlphp xml-security library to version 2.3.1 or 1.13.9 or later, where the vulnerability is patched. Prior to upgrading, conduct an inventory of all systems using simplesamlphp to identify affected versions. Implement network-level protections such as restricting access to SAML endpoints to trusted IP ranges and deploying web application firewalls (WAFs) with rules to detect anomalous XML payloads. Monitor authentication logs and XML processing events for unusual patterns that may indicate exploitation attempts. Where possible, employ additional encryption or tokenization layers around sensitive XML data to reduce exposure. Conduct thorough security testing and code reviews of SAML integrations to ensure no residual weaknesses exist. Finally, maintain an incident response plan tailored to identity federation breaches to quickly respond if exploitation is detected.

Description

xml-security is a library that implements XML signatures and encryption. Prior to versions 2.3.1 and 1.13.9, XML nodes encrypted with either aes-128-gcm, aes-192-gcm, or aes-256-gcm lack validation of the authentication tag length. An attacker can use this to brute-force an authentication tag, recover the GHASH key, and decrypt the encrypted nodes. It also allows to forge arbitrary ciphertexts without knowing the encryption key. This vulnerability is fixed in 2.3.1 and 1.13.9.

Impact

This vulnerability poses a significant threat to organizations relying on simplesamlphp xml-security for SAML authentication and XML encryption. Successful exploitation allows attackers to decrypt sensitive XML data, potentially exposing confidential information such as authentication tokens, user credentials, or personally identifiable information. Additionally, the ability to forge ciphertexts undermines data integrity, enabling attackers to inject malicious or manipulated data into authentication workflows. This can lead to unauthorized access, privilege escalation, or session hijacking. Since simplesamlphp is widely used in identity federation and single sign-on (SSO) implementations, the impact could extend to numerous enterprise environments, government agencies, and cloud services. The lack of requirement for authentication or user interaction means attackers can exploit this vulnerability remotely and stealthily, increasing the risk of widespread compromise. Although availability is not directly affected, the confidentiality and integrity breaches can have cascading effects on organizational security posture and trust in identity systems.

CWE-354Improper Validation of Integrity Check Value (opens in a new tab)
Base weaknessLikelihood of exploit: Medium
The product does not validate or incorrectly validates the integrity check values or "checksums" of a message.
Implementation
The protocol specification describes the algorithm used for calculating the checksum. It is then a matter of implementing the calculation and verifying that the calculated checksum and the received checksum match.
OWASP Cheat Sheets
XML Security (opens in a new tab)
REST Security (opens in a new tab)
JSON Web Token for Java (opens in a new tab)
OWASP ASVS 4.0.3
V11.1.7 (opens in a new tab)
V13.3.2 (opens in a new tab)
V3.5.3 (opens in a new tab)
Attack patterns
Checksum Spoofing (opens in a new tab)
Padding Oracle Crypto Attack (opens in a new tab)
Manipulating Writeable Configuration Files (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 21 Mar 2026, 00:37 UTC

WeaknessesCWE-354

Technical details

References

Community reviews

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