expat: hash table collisions CPU usage DoS
Published Jul 3, 2012
4.3
MEDIUMCVSS 2.0
EPSS 5.72%
Description
The XML parser (xmlparse.c) in expat before 2.1.0 computes hash values without restricting the ability to trigger hash collisions predictably, which allows context-dependent attackers to cause a denial of service (CPU consumption) via an XML file with many identifiers with the same value.
Affected products
No data.
Configuration 1
- < 2.1.0
Configuration 2
Configuration 3
- 6.0
- 7.0
Configuration 4
- 8.04
- 10.04
- 11.04
- 11.10
- 12.04
Configuration 6
- 2.0
- 5.0
- 6.0
- 6.2
- 5.0
- 6.0
- 6.2
- 5.0
- 6.0
No data.
Red Hat Enterprise Linux 5
expat-0:1.95.8-11.el5_8
Fixed · RHSA-2012:0731
Red Hat Enterprise Linux 6
expat-0:2.0.1-11.el6_2
Fixed · RHSA-2012:0731
Red Hat JBoss Core Services
n/a
Fixed · RHSA-2016:2957
Red Hat JBoss Enterprise Application Platform 6.4
n/a
Fixed · RHSA-2017:3239
Red Hat JBoss Web Server 2.1
expat
Fixed · RHSA-2016:0062
Red Hat Directory Server 8
expat
Affected
Red Hat Enterprise Linux 4
expat
Will not fix
Red Hat Enterprise Linux 5
xmlrpc-c
Will not fix
Red Hat Enterprise Linux 6
compat-expat1
Will not fix
Red Hat Enterprise Linux 6
mingw32-expat
Affected
Red Hat JBoss Enterprise Application Platform 6
expat
Affected
Red Hat JBoss Enterprise Web Server 3
expat
Affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | expat-0:1.95.8-11.el5_8 | Fixed | RHSA-2012:0731 |
| Red Hat Enterprise Linux 6 | expat-0:2.0.1-11.el6_2 | Fixed | RHSA-2012:0731 |
| Red Hat JBoss Core Services | n/a | Fixed | RHSA-2016:2957 |
| Red Hat JBoss Enterprise Application Platform 6.4 | n/a | Fixed | RHSA-2017:3239 |
| Red Hat JBoss Web Server 2.1 | expat | Fixed | RHSA-2016:0062 |
| Red Hat Directory Server 8 | expat | Affected | n/a |
| Red Hat Enterprise Linux 4 | expat | Will not fix | n/a |
| Red Hat Enterprise Linux 5 | xmlrpc-c | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | compat-expat1 | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | mingw32-expat | Affected | n/a |
| Red Hat JBoss Enterprise Application Platform 6 | expat | Affected | n/a |
| Red Hat JBoss Enterprise Web Server 3 | expat | Affected | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
No CVSS v3.0 score for this CVE.
AV:N/AC:M/Au:N/C:N/I:N/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 (10 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 5.72% (0.05724) | 92.80th | v5 (v2026.06.15) |
| Jun 15, 2026 | 5.72% (0.05724) | 92.03th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.55% (0.00545) | 65.80th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.42% (0.00418) | 74.96th | v3 (v2023.03.01) |
| Feb 8, 2024 | 0.42% (0.00418) | 73.44th | v3 (v2023.03.01) |
| Jul 28, 2023 | 0.42% (0.00418) | 70.73th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.40% (0.00399) | 69.44th | v3 (v2023.03.01) |
| Mar 6, 2023 | 2.69% (0.02686) | 82.85th | v2 (v2022.01.01) |
| Apr 1, 2022 | 2.69% (0.02686) | 81.17th | v2 (v2022.01.01) |
| Feb 4, 2022 | 2.69% (0.02686) | 62.66th | v2 (v2022.01.01) |
References (26)
- http://bugs.python.org/issue13703#msg151870 x_refsource_MISCIssue TrackingThird Party Advisory
- http://lists.apple.com/archives/security-announce/2013/Oct/msg00004.html vendor-advisoryx_refsource_APPLEBroken LinkMailing List
- http://lists.apple.com/archives/security-announce/2015/Dec/msg00005.html vendor-advisoryx_refsource_APPLEBroken LinkMailing List
- http://mail.libexpat.org/pipermail/expat-discuss/2012-March/002768.html mailing-listx_refsource_MLISTBroken Link
- http://rhn.redhat.com/errata/RHSA-2012-0731.html vendor-advisoryx_refsource_REDHATThird Party Advisory
- http://rhn.redhat.com/errata/RHSA-2016-0062.html vendor-advisoryx_refsource_REDHATThird Party Advisory
- http://rhn.redhat.com/errata/RHSA-2016-2957.html vendor-advisoryx_refsource_REDHATThird Party Advisory
- http://secunia.com/advisories/49504 third-party-advisoryx_refsource_SECUNIANot Applicable
- http://secunia.com/advisories/51024 third-party-advisoryx_refsource_SECUNIANot Applicable
- http://secunia.com/advisories/51040 third-party-advisoryx_refsource_SECUNIANot Applicable
- http://sourceforge.net/projects/expat/files/expat/2.1.0/ x_refsource_CONFIRMRelease NotesThird Party Advisory
- http://sourceforge.net/tracker/?func=detail&atid=110127&aid=3496608&group_id=10127 x_refsource_CONFIRMThird Party Advisory
- http://www.debian.org/security/2012/dsa-2525 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- http://www.mandriva.com/security/advisories?name=MDVSA-2012:041 vendor-advisoryx_refsource_MANDRIVABroken Link
- http://www.oracle.com/technetwork/topics/security/bulletinjul2016-3090568.html x_refsource_CONFIRMThird Party Advisory
- http://www.securityfocus.com/bid/52379 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.ubuntu.com/usn/USN-1527-1 vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- http://www.ubuntu.com/usn/USN-1613-1 vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- http://www.ubuntu.com/usn/USN-1613-2 vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://access.redhat.com/security/cve/CVE-2012-0876 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=786617 Issue Tracking
- https://kc.mcafee.com/corporate/index?page=content&id=SB10365 x_refsource_CONFIRMBroken Link
- https://nvd.nist.gov/vuln/detail/CVE-2012-0876
- https://support.apple.com/HT205637 x_refsource_CONFIRMThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2012-0876
- https://www.tenable.com/security/tns-2016-20 x_refsource_CONFIRMThird Party Advisory
Change history (0)
No recorded changes yet.