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CVE-2016-10149· NVD / CVE Program· CNA mitre

XML External Entity (XXE) vulnerability in PySAML2 4.4.0 and earlier allows remote attackers to read arbitrary files via a crafted SAML XML

XML External Entity (XXE) vulnerability in PySAML2 4.4.0 and earlier allows remote attackers to read arbitrary files via a crafted SAML XML request or response.

HighCVSS 7.5 · v3.0—No exploit Fix available
Published
Mar 24, 2017
Updated
Jun 16, 2026
EPSS
5.0% · 92th percentile
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Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
2 / 30 · 5.0%

Affected systems

VendorProduct
pysaml2 projectpysaml2
debiandebian linux

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • debian debian linux8.0
  • pysaml2 project pysaml2up to 4.4.0 inclusive

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12python-pysaml2before 3.0.0-53.0.0-5
Debian:8python-pysaml2before 2.0.0-1+deb8u12.0.0-1+deb8u1
PyPIpysaml2before 4.5.04.5.0
Red Hat:openstack:8::el7python-defusedxmlbefore 0:0.5.0-1.el7ost0:0.5.0-1.el7ost
Red Hat:openstack:8::el7python-pysaml2before 0:3.0.2-3.el7ost0:3.0.2-3.el7ost
SUSE:OpenStack Cloud 6python-defusedxmlbefore 0.4.1-2.10.4.1-2.1
SUSE:OpenStack Cloud 6python-pysaml2before 2.4.0-3.12.4.0-3.1

Same product

pysaml2 project: all records

Other highest-scoring records for the same primary product.

  • CVE-2016-10127PySAML2 allows remote attackers to conduct XML external entity (XXE) attacks via a crafted SAML XML request or response.
    37Monitor
  • CVE-2017-1000433pysaml2 version 4.4.0 and older accept any password when run with python optimizations enabled.
    33Monitor
  • CVE-2020-5390PySAML2 before 5.0.0 does not check that the signature in a SAML document is enveloped and thus signature wrapping is effective, i.e., it is
    30Monitor
  • CVE-2021-21239Open default xmlsec1 key-type preference
    26Monitor
  • CVE-2021-21238SAML XML Signature wrapping
    26Monitor
  • CVE-2017-1000246Python package pysaml2 version 4.4.0 and earlier reuses the initialization vector across encryptions in the IDP server, resulting in weak en
    21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:python-pysaml23.0.0-5 · Debian:12Package registry (OSV)
PyPI:pysaml24.5.0Package registry (OSV)
red hat:python-defusedxml0:0.5.0-1.el7ost · Red Hat:openstack:8::el7Package registry (OSV)
red hat:python-pysaml20:3.0.2-3.el7ost · Red Hat:openstack:8::el7Package registry (OSV)
suse:python-defusedxml0.4.1-2.1 · SUSE:OpenStack Cloud 6Package registry (OSV)
suse:python-pysaml22.4.0-3.1 · SUSE:OpenStack Cloud 6Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-611 · Improper Restriction of XML External Entity Reference

CVSS vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Noroxi analysis

No Noroxi analysis for this record yet

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Change log

  1. Fix✗ → ✓

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References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records