libxml2: Mishandling parameter-entity references
Published Nov 23, 2017
9.8
CRITICALCVSS 3.0
EPSS 4.33%
Description
parser.c in libxml2 before 2.9.5 mishandles parameter-entity references because the NEXTL macro calls the xmlParserHandlePEReference function in the case of a '%' character in a DTD name.
Affected products
No data.
No data.
CloudForms Management Engine 5
rh-ruby22-rubygem-nokogiri
Will not fix
Red Hat Enterprise Linux 5
libxml2
Will not fix
Red Hat Enterprise Linux 6
libxml2
Will not fix
Red Hat Enterprise Linux 7
libxml2
Will not fix
Red Hat Enterprise MRG 2
rubygem-nokogiri
Will not fix
Red Hat Satellite 6
ruby193-rubygem-nokogiri
Will not fix
Red Hat Satellite 6
tfm-rubygem-nokogiri
Will not fix
Red Hat Software Collections
rh-passenger40-rubygem-nokogiri
Not affected
Red Hat Software Collections
rh-ror42-rubygem-nokogiri
Not affected
Red Hat Software Collections
rh-ror50-rubygem-nokogiri
Not affected
Red Hat Subscription Asset Manager
ruby193-rubygem-nokogiri
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| CloudForms Management Engine 5 | rh-ruby22-rubygem-nokogiri | Will not fix | n/a |
| Red Hat Enterprise Linux 5 | libxml2 | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | libxml2 | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | libxml2 | Will not fix | n/a |
| Red Hat Enterprise MRG 2 | rubygem-nokogiri | Will not fix | n/a |
| Red Hat Satellite 6 | ruby193-rubygem-nokogiri | Will not fix | n/a |
| Red Hat Satellite 6 | tfm-rubygem-nokogiri | Will not fix | n/a |
| Red Hat Software Collections | rh-passenger40-rubygem-nokogiri | Not affected | n/a |
| Red Hat Software Collections | rh-ror42-rubygem-nokogiri | Not affected | n/a |
| Red Hat Software Collections | rh-ror50-rubygem-nokogiri | Not affected | n/a |
| Red Hat Subscription Asset Manager | ruby193-rubygem-nokogiri | Will not fix | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
This issue affects the versions of rubygem-nokogiri as shipped with Red Hat Subscription Asset Manager 1.x. Red Hat Product Security has rated this issue as having Moderate security impact. A future update may address this issue. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/. This issue affects the versions of libxml2 as shipped with Red Hat Enterprise Linux 5, 6, and 7. Red Hat Product Security has rated this issue as having Moderate security impact. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/. This issue affects the versions of rubygem-nokogiri on CloudForms 5 as it uses the Red Hat Enterprise copy of libxml2 as shipped with Red Hat Enterprise Linux 7. Red Hat Product Security has rated this issue as having Moderate security impact. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/. This issue affects the versions of rubygem-nokogiri on Satellite 6.0, 6.1 and 6.2 as it uses the Red Hat Enterprise copy of libxml2 as shipped with Red Hat Enterprise Linux 7. Red Hat Product Security has rated this issue as having Moderate security impact. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/. Please note that Satellite version 6.3 no longer ships rubygem-nokogir, but instead uses a version of rubygem-nokogiri from another software channel. Red Hat Enterprise Linux 5 is now in Extended Life Cycle phase of the support and maintenance life cycle. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/. Red Hat Enterprise Linux 6 is now in Production 3 Phase of the support and maintenance life cycle. This has been rated as having Moderate security impact and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
1 other source (Red Hat) ▾
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AV:N/AC:L/Au:N/C:P/I:P/A:P
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 2, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (17 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 2, 2026 | 4.33% (0.04332) | 90.90th | v5 (v2026.06.15) |
| Jun 15, 2026 | 4.45% (0.04452) | 90.16th | v5 (v2026.06.15) |
| Mar 30, 2025 | 1.09% (0.01086) | 75.90th | v4 (v2025.03.14) |
| Mar 29, 2025 | 3.32% (0.03320) | 78.56th | v4 (v2025.03.14) |
| Jul 20, 2024 | 0.60% (0.00601) | 78.67th | v3 (v2023.03.01) |
| Feb 8, 2024 | 0.60% (0.00601) | 77.79th | v3 (v2023.03.01) |
| May 8, 2023 | 0.60% (0.00601) | 75.25th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.85% (0.00853) | 79.67th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.02% (0.01018) | 40.69th | v2 (v2022.01.01) |
| Sep 10, 2022 | 1.02% (0.01018) | 38.88th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.02% (0.01018) | 36.86th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.02% (0.01018) | 19.50th | v2 (v2022.01.01) |
| Feb 3, 2022 | 1.25% (0.01247) | 30.57th | v1 |
| Jan 6, 2022 | 1.25% (0.01247) | 29.93th | v1 |
| Sep 1, 2021 | 1.25% (0.01247) | 68.62th | v1 |
| Jul 21, 2021 | 1.25% (0.01247) | 0.00th | v1 |
| Apr 14, 2021 | 1.04% (0.01040) | 0.00th | v1 |
References (9)
- http://xmlsoft.org/news.html x_refsource_CONFIRMRelease NotesVendor Advisory
- https://access.redhat.com/security/cve/CVE-2017-16931 Vendor Advisory
- https://bugzilla.gnome.org/show_bug.cgi?id=766956 x_refsource_CONFIRMPermissions Required
- https://bugzilla.redhat.com/show_bug.cgi?id=1517307 Issue Tracking
- https://github.com/GNOME/libxml2/commit/e26630548e7d138d2c560844c43820b6767251e3 x_refsource_CONFIRMPatchThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2017/11/msg00041.html mailing-listx_refsource_MLIST
- https://nvd.nist.gov/vuln/detail/CVE-2017-16931
- https://www.cve.org/CVERecord?id=CVE-2017-16931
- https://www.oracle.com//security-alerts/cpujul2021.html x_refsource_MISC
| Link | Providers | Tags |
|---|---|---|
| http://xmlsoft.org/news.html | x_refsource_CONFIRMRelease NotesVendor Advisory | |
| https://access.redhat.com/security/cve/CVE-2017-16931 | Vendor Advisory | |
| https://bugzilla.gnome.org/show_bug.cgi?id=766956 | x_refsource_CONFIRMPermissions Required | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1517307 | Issue Tracking | |
| https://github.com/GNOME/libxml2/commit/e26630548e7d138d2c560844c43820b6767251e3 | x_refsource_CONFIRMPatchThird Party Advisory | |
| https://lists.debian.org/debian-lts-announce/2017/11/msg00041.html | mailing-listx_refsource_MLIST | |
| https://nvd.nist.gov/vuln/detail/CVE-2017-16931 | ||
| https://www.cve.org/CVERecord?id=CVE-2017-16931 | ||
| https://www.oracle.com//security-alerts/cpujul2021.html | x_refsource_MISC |
Change history (0)
No recorded changes yet.