Cyber Resilience

CVE-2026-32600

Simplesamlphp Xml-Security ≤ 1.13.9

Public PoC
Published
16 March 2026
Modified
17 March 2026
Patch / advisory
CVSS Score v3.1 8.2
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
EPSS Score 0.0015 5th percentile
Risk Priority 59 floored blend · peak EPSS

Summary

CVE-2026-32600 is a high-severity Improper Validation of Integrity Check Value (CWE-354) vulnerability in Simplesamlphp Xml-Security. Its CVSS base score is 8.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Supply Chain Compromise (T1195); ranked at the 5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SC-13 (Cryptographic Protection) and SC-8 (Transmission Confidentiality and Integrity) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-32600 affects the xml-security library, which implements XML signatures and encryption. In versions prior to 2.3.1 and 1.13.9, XML nodes encrypted using AES-128-GCM, AES-192-GCM, or AES-256-GCM fail to validate the authentication tag length, violating proper GCM handling as described in CWE-354 (Insufficient Entropy in Random Number Generator, tied to authentication tag issues). This flaw enables cryptographic weaknesses in XML encryption processing.

A remote, unauthenticated attacker with network access can exploit this vulnerability with low complexity and no user interaction, as indicated by its CVSS v3.1 base score of 8.2 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N). Successful exploitation allows brute-forcing the authentication tag to recover the GHASH key, decrypting affected XML nodes and exposing confidential data. Additionally, attackers can forge arbitrary ciphertexts without knowledge of the encryption key, potentially enabling integrity violations.

The xml-security GitHub security advisory (GHSA-r353-4845-pr5p) and related commits detail the fix, recommending an upgrade to version 2.3.1 or 1.13.9, where authentication tag length validation is properly enforced. Practitioners should review dependencies using this library, such as in SimpleSAMLphp integrations, and apply patches immediately to mitigate risks.

EU & UK References

Vulnerability Data

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…

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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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1195 Supply Chain Compromise Initial Access
Adversaries may manipulate products or product delivery mechanisms prior to receipt by a final consumer for the purpose of data or system compromise.
T1195.001 Compromise Software Dependencies and Development Tools Initial Access
Adversaries may manipulate software dependencies and development tools prior to receipt by a final consumer for the purpose of data or system compromise.
T1195.002 Compromise Software Supply Chain Initial Access
Adversaries may manipulate application software prior to receipt by a final consumer for the purpose of data or system compromise.
T1565 Data Manipulation Impact
Adversaries may insert, delete, or manipulate data in order to influence external outcomes or hide activity, thus threatening the integrity of the data.
T1565.002 Transmitted Data Manipulation Impact
Adversaries may alter data en route to storage or other systems in order to manipulate external outcomes or hide activity, thus threatening the integrity of the data.
T1601 Modify System Image Defense Impairment
Adversaries may make changes to the operating system of embedded network devices to weaken defenses and provide new capabilities for themselves.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-49087Same product: Simplesamlphp Xml-Security
CVE-2023-23119Shared CWE-354
CVE-2023-30673Shared CWE-354
CVE-2024-48930Shared CWE-354
CVE-2026-9653Shared CWE-354
CVE-2023-31438Shared CWE-354
CVE-2023-31439Shared CWE-354
CVE-2023-31437Shared CWE-354
CVE-2024-52550Shared CWE-354
CVE-2024-23461Shared CWE-354

Affected Assets

simplesamlphp
xml-security
≤ 1.13.9 · 2.0.0 — 2.3.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 10 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V10.4.12

Mitigating Controls (NIST 800-53 r5) AI

Requires integrity verification tools that detect unauthorized changes when checksum validation is missing or flawed.

Mandates cryptographic mechanisms that include integrity protection, preventing improper checksum validation.

Requires protection of transmitted information integrity, directly mandating correct validation of integrity checks.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.DS-01 mostly match
prevents

Requires cryptographic hashes and signatures that directly enforce integrity-check validation for data at rest.

PR.DS-02 mostly match
prevents

Requires cryptographic hashes and signatures that directly enforce integrity-check validation for data in transit.

ID.RA-09 partial match
prevents

Mandates pre-acquisition integrity assessment, addressing only the initial portion of the weakness lifecycle.

RC.RP-03 partial match
prevents

Requires verification of backup integrity, covering validation only within recovery scenarios.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Cryptographic controls mandate integrity mechanisms whose correct validation directly prevents CWE-354.

prevents

Secure coding standards require proper implementation and validation of checksums or MACs.

finds

Security testing can detect missing integrity validation but does not itself implement the control.

prevents

Application security requirements include integrity checks on messages and data, mitigating improper validation.

none

Network security policies may require integrity protection on transit data, indirectly addressing the weakness.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. prevents CWE-354
  • V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-354
Oracle Linux 9 (1 rule)
  • V-271523 OL 9 must check the GPG signature of locally installed software packages before installation. prevents CWE-354
RHEL 7 (2 rules)
  • V-204447 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-354
  • V-204448 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-354
RHEL 8 (2 rules)
  • V-230264 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-354
  • V-230265 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-354

References