expat: Undefined behavior and pointer overflows
Published Jun 30, 2016
8.1
HIGHCVSS 3.1
EPSS 11.95%
Description
The overflow protection in Expat is removed by compilers with certain optimization settings, which allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via crafted XML data. NOTE: this vulnerability exists because of an incomplete fix for CVE-2015-1283 and CVE-2015-2716.
Affected products
No data.
Configuration 1
- ≤ 2.1.1
Configuration 2
- 12.04
Configuration 3
- < 6.5.1
No data.
Red Hat Directory Server 8
expat
Under investigation
Red Hat Enterprise Linux 5
PyXML
Not affected
Red Hat Enterprise Linux 5
apr-util
Not affected
Red Hat Enterprise Linux 5
dasher
Not affected
Red Hat Enterprise Linux 5
expat
Will not fix
Red Hat Enterprise Linux 5
firefox
Will not fix
Red Hat Enterprise Linux 5
ghostscript
Not affected
Red Hat Enterprise Linux 5
httpd
Not affected
Red Hat Enterprise Linux 5
thunderbird
Will not fix
Red Hat Enterprise Linux 5
xmlrpc-c
Will not fix
Red Hat Enterprise Linux 5
xulrunner
Will not fix
Red Hat Enterprise Linux 6
PyXML
Not affected
Red Hat Enterprise Linux 6
apr-util
Not affected
Red Hat Enterprise Linux 6
compat-expat1
Will not fix
Red Hat Enterprise Linux 6
firefox
Affected
Red Hat Enterprise Linux 6
ghostscript
Not affected
Red Hat Enterprise Linux 6
httpd
Not affected
Red Hat Enterprise Linux 6
texlive
Not affected
Red Hat Enterprise Linux 6
thunderbird
Affected
Red Hat Enterprise Linux 6
xulrunner
Will not fix
Red Hat Enterprise Linux 7
apr-util
Not affected
Red Hat Enterprise Linux 7
expat
Will not fix
Red Hat Enterprise Linux 7
firefox
Affected
Red Hat Enterprise Linux 7
thunderbird
Affected
Red Hat Enterprise Linux 7
xulrunner
Will not fix
Red Hat JBoss Core Services
expat
Not affected
Red Hat JBoss Enterprise Application Platform 6
expat
Not affected
Red Hat JBoss Enterprise Web Server 2
expat
Not affected
Red Hat JBoss Enterprise Web Server 3
expat
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Directory Server 8 | expat | Under investigation | n/a |
| Red Hat Enterprise Linux 5 | PyXML | Not affected | n/a |
| Red Hat Enterprise Linux 5 | apr-util | Not affected | n/a |
| Red Hat Enterprise Linux 5 | dasher | Not affected | n/a |
| Red Hat Enterprise Linux 5 | expat | Will not fix | n/a |
| Red Hat Enterprise Linux 5 | firefox | Will not fix | n/a |
| Red Hat Enterprise Linux 5 | ghostscript | Not affected | n/a |
| Red Hat Enterprise Linux 5 | httpd | Not affected | n/a |
| Red Hat Enterprise Linux 5 | thunderbird | Will not fix | n/a |
| Red Hat Enterprise Linux 5 | xmlrpc-c | Will not fix | n/a |
| Red Hat Enterprise Linux 5 | xulrunner | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | PyXML | Not affected | n/a |
| Red Hat Enterprise Linux 6 | apr-util | Not affected | n/a |
| Red Hat Enterprise Linux 6 | compat-expat1 | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | firefox | Affected | n/a |
| Red Hat Enterprise Linux 6 | ghostscript | Not affected | n/a |
| Red Hat Enterprise Linux 6 | httpd | Not affected | n/a |
| Red Hat Enterprise Linux 6 | texlive | Not affected | n/a |
| Red Hat Enterprise Linux 6 | thunderbird | Affected | n/a |
| Red Hat Enterprise Linux 6 | xulrunner | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | apr-util | Not affected | n/a |
| Red Hat Enterprise Linux 7 | expat | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | firefox | Affected | n/a |
| Red Hat Enterprise Linux 7 | thunderbird | Affected | n/a |
| Red Hat Enterprise Linux 7 | xulrunner | Will not fix | n/a |
| Red Hat JBoss Core Services | expat | Not affected | n/a |
| Red Hat JBoss Enterprise Application Platform 6 | expat | Not affected | n/a |
| Red Hat JBoss Enterprise Web Server 2 | expat | Not affected | n/a |
| Red Hat JBoss Enterprise Web Server 3 | expat | Not affected | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
No CVSS v3.0 score for this CVE.
AV:N/AC:M/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 1, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (18 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 11.95% (0.11946) | 96.00th | v5 (v2026.06.15) |
| Jun 15, 2026 | 11.95% (0.11946) | 95.57th | v5 (v2026.06.15) |
| Mar 4, 2026 | 2.27% (0.02271) | 84.38th | v4 (v2025.03.14) |
| Mar 1, 2026 | 3.51% (0.03506) | 87.44th | v4 (v2025.03.14) |
| Sep 16, 2025 | 1.81% (0.01812) | 82.17th | v4 (v2025.03.14) |
| Jun 4, 2025 | 3.42% (0.03420) | 86.88th | v4 (v2025.03.14) |
| Jun 1, 2025 | 4.58% (0.04580) | 88.71th | v4 (v2025.03.14) |
| May 5, 2025 | 3.42% (0.03420) | 86.77th | v4 (v2025.03.14) |
| May 1, 2025 | 4.58% (0.04580) | 88.64th | v4 (v2025.03.14) |
| Mar 30, 2025 | 3.43% (0.03425) | 86.35th | v4 (v2025.03.14) |
| Mar 29, 2025 | 4.81% (0.04815) | 82.11th | v4 (v2025.03.14) |
| Mar 17, 2025 | 2.55% (0.02547) | 84.44th | v4 (v2025.03.14) |
| Dec 12, 2024 | 1.36% (0.01365) | 86.81th | v3 (v2023.03.01) |
| May 4, 2024 | 1.36% (0.01365) | 86.15th | v3 (v2023.03.01) |
| Mar 7, 2023 | 1.36% (0.01365) | 84.15th | v3 (v2023.03.01) |
| Mar 6, 2023 | 4.55% (0.04550) | 88.84th | v2 (v2022.01.01) |
| Apr 1, 2022 | 4.55% (0.04550) | 87.73th | v2 (v2022.01.01) |
| Feb 4, 2022 | 4.55% (0.04550) | 74.11th | v2 (v2022.01.01) |
References (10)
- http://www.securityfocus.com/bid/91528 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.ubuntu.com/usn/USN-3013-1 vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://access.redhat.com/security/cve/CVE-2016-4472 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1344251 x_refsource_CONFIRMIssue TrackingPatchThird Party Advisory
- https://kc.mcafee.com/corporate/index?page=content&id=SB10365 x_refsource_CONFIRMThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2016-4472
- https://security.gentoo.org/glsa/201701-21 vendor-advisoryx_refsource_GENTOOThird Party Advisory
- https://sourceforge.net/p/expat/code_git/ci/f0bec73b018caa07d3e75ec8dd967f3785d71bde x_refsource_CONFIRMPatchThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2016-4472
- https://www.tenable.com/security/tns-2016-20 x_refsource_CONFIRMThird Party Advisory
| Link | Providers | Tags |
|---|---|---|
| http://www.securityfocus.com/bid/91528 | vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry | |
| http://www.ubuntu.com/usn/USN-3013-1 | vendor-advisoryx_refsource_UBUNTUThird Party Advisory | |
| https://access.redhat.com/security/cve/CVE-2016-4472 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1344251 | x_refsource_CONFIRMIssue TrackingPatchThird Party Advisory | |
| https://kc.mcafee.com/corporate/index?page=content&id=SB10365 | x_refsource_CONFIRMThird Party Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2016-4472 | ||
| https://security.gentoo.org/glsa/201701-21 | vendor-advisoryx_refsource_GENTOOThird Party Advisory | |
| https://sourceforge.net/p/expat/code_git/ci/f0bec73b018caa07d3e75ec8dd967f3785d71bde | x_refsource_CONFIRMPatchThird Party Advisory | |
| https://www.cve.org/CVERecord?id=CVE-2016-4472 | ||
| https://www.tenable.com/security/tns-2016-20 | x_refsource_CONFIRMThird Party Advisory |
Change history (0)
No recorded changes yet.