In libexpat before 2.2.8, crafted XML input could fool the parser into changing from DTD parsing to document parsing too early; a consecutiv
Noroxi assessment
Priority: Monitor (action score 32/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 6.6% (FIRST EPSS); higher than 93.7% of all records.
- 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.
- Fixed version: expat (Alpine:v3.10) 2.2.7-r1; python2 (Alpine:v3.10) 2.7.17-r0; expat (Debian:10) 2.2.6-2+deb10u1.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to expat (Alpine:v3.10) 2.2.7-r1; python2 (Alpine:v3.10) 2.7.17-r0; expat (Debian:10) 2.2.6-2+deb10u1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
In libexpat before 2.2.8, crafted XML input could fool the parser into changing from DTD parsing to document parsing too early; a consecutive call to XML_GetCurrentLineNumber (or XML_GetCurrentColumnNumber) then resulted in a heap-based buffer over-read.
- BDU:2019-03643
- DLA-1912-1
- DLA-1987-1
- DLA-1997-1
- DSA-4530-1
- DSA-4549-1
- DSA-4571-1
- openSUSE-SU-2019:2204-1
- openSUSE-SU-2019:2205-1
- openSUSE-SU-2019:2451-1
- openSUSE-SU-2019:2452-1
- openSUSE-SU-2019:2459-1
- openSUSE-SU-2019:2464-1
- openSUSE-SU-2024:10748-1
- RHSA-2019:3193
- RHSA-2019:3196
- RHSA-2019:3210
- RHSA-2019:3237
- RHSA-2019:3756
- RHSA-2020:2644
- Published
- Sep 4, 2019
- Updated
- Oct 14, 2026
- EPSS
- 6.6% · 93th percentile
- CWE
- CWE-125
Report tools
Action score
32
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 2 / 30 · 6.6%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 7.5
- CNA · mitre
- 6.5
- 1.0 point gap
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| libexpat project | libexpat | cpe:2.3:a:libexpat_project:libexpat |
| python | python | cpe:2.3:a:python:python |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- libexpat project libexpatbefore 2.2.8
- python python2.7.0 and later · before 2.7.17
- python python3.5.0 and later · before 3.5.8
- python python3.6.0 and later · before 3.6.10
- python python3.7.0 and later · before 3.7.5
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.10 | expat | before 2.2.7-r1 | 2.2.7-r1 |
| Alpine:v3.10 | python2 | before 2.7.17-r0 | 2.7.17-r0 |
| Debian:10 | expat | before 2.2.6-2+deb10u1 | 2.2.6-2+deb10u1 |
| Debian:10 | firefox-esr | before 68.2.0esr-1~deb10u1 | 68.2.0esr-1~deb10u1 |
| Debian:10 | thunderbird | before 1:68.2.2-1~deb10u1 | 1:68.2.2-1~deb10u1 |
| Debian:12 | expat | before 2.2.7-2 | 2.2.7-2 |
| Debian:12 | firefox-esr | before 68.2.0esr-1 | 68.2.0esr-1 |
| Debian:12 | libxmltok | from 0 | — |
| Debian:12 | thunderbird | before 1:68.2.1-1 | 1:68.2.1-1 |
| Debian:8 | expat | before 2.1.0-6+deb8u6 | 2.1.0-6+deb8u6 |
| Debian:8 | firefox-esr | before 68.2.0esr-1~deb8u1 | 68.2.0esr-1~deb8u1 |
| Debian:8 | thunderbird | before 1:68.2.2-1~deb8u1 | 1:68.2.2-1~deb8u1 |
| Debian:9 | expat | before 2.2.0-2+deb9u3 | 2.2.0-2+deb9u3 |
| Debian:9 | firefox-esr | before 68.2.0esr-1~deb9u2 | 68.2.0esr-1~deb9u2 |
| Debian:9 | thunderbird | before 1:68.2.2-1~deb9u1 | 1:68.2.2-1~deb9u1 |
| openSUSE:Leap 15.0 | expat | before 2.2.5-lp150.2.6.1 | 2.2.5-lp150.2.6.1 |
| openSUSE:Leap 15.0 | firefox-esr-branding-openSUSE | before 68-lp150.3.3.1 | 68-lp150.3.3.1 |
| openSUSE:Leap 15.0 | MozillaFirefox | before 68.2.0-lp150.3.71.1 | 68.2.0-lp150.3.71.1 |
| openSUSE:Leap 15.0 | MozillaFirefox-branding-openSUSE | before 68-lp150.3.3.1 | 68-lp150.3.3.1 |
| openSUSE:Leap 15.0 | MozillaThunderbird | before 68.2.1-lp150.3.54.1 | 68.2.1-lp150.3.54.1 |
| openSUSE:Leap 15.1 | expat | before 2.2.5-lp151.3.6.1 | 2.2.5-lp151.3.6.1 |
| openSUSE:Leap 15.1 | firefox-esr-branding-openSUSE | before 68-lp151.3.3.1 | 68-lp151.3.3.1 |
| openSUSE:Leap 15.1 | MozillaFirefox | before 68.2.0-lp151.2.18.2 | 68.2.0-lp151.2.18.2 |
| openSUSE:Leap 15.1 | MozillaFirefox-branding-openSUSE | before 68-lp151.3.3.1 | 68-lp151.3.3.1 |
+93
Same product
libexpat project: all recordsOther highest-scoring records for the same primary product.
- CVE-2022-25236xmlparse.c in Expat (aka libexpat) before 2.4.5 allows attackers to insert namespace-separator characters into namespace URIs.50Plan
- CVE-2022-23852Expat (aka libexpat) before 2.4.4 has a signed integer overflow in XML_GetBuffer, for configurations with a nonzero XML_CONTEXT_BYTES.41Plan
- CVE-2022-22822addBinding in xmlparse.c in Expat (aka libexpat) before 2.4.3 has an integer overflow.41Plan
Published before and after this one in the same product
- ← EarlierCVE-2017-11742Jul 30, 2017 · The writeRandomBytes_RtlGenRandom function in xmlparse.c in libexpat in Expat 2.2.1 and 2.2.2 on Windows allows local users to gain privileg31Monitor
- ← EarlierCVE-2018-20843Jun 24, 2019 · In libexpat in Expat before 2.2.7, XML input including XML names that contain a large number of colons could make the XML parser consume a h32Monitor
- Later →CVE-2021-45960Jan 1, 2022 · In Expat (aka libexpat) before 2.4.3, a left shift by 29 (or more) places in the storeAtts function in xmlparse.c can lead to realloc misbeh36Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| alpine:expat | 2.2.7-r1 · Alpine:v3.10 | Package registry (OSV) |
| alpine:python2 | 2.7.17-r0 · Alpine:v3.10 | Package registry (OSV) |
| debian:expat | 2.2.7-2 · Debian:12 | Package registry (OSV) |
| debian:firefox-esr | 68.2.0esr-1 · Debian:12 | Package registry (OSV) |
| debian:thunderbird | 1:68.2.1-1 · Debian:12 | Package registry (OSV) |
| opensuse:expat | 2.2.5-lp150.2.6.1 · openSUSE:Leap 15.0 | Package registry (OSV) |
| opensuse:firefox-esr-branding-openSUSE | 68-lp151.3.3.1 · openSUSE:Leap 15.1 | Package registry (OSV) |
| opensuse:MozillaFirefox | 68.2.0-lp151.2.18.2 · openSUSE:Leap 15.1 | Package registry (OSV) |
| opensuse:MozillaFirefox-branding-openSUSE | 68-lp151.3.3.1 · openSUSE:Leap 15.1 | Package registry (OSV) |
| opensuse:MozillaThunderbird | 68.2.1-lp151.2.16.1 · openSUSE:Leap 15.1 | Package registry (OSV) |
| red hat:firefox | 0:68.2.0-1.el7_7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:firefox-debuginfo | 0:68.2.0-1.el7_7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:firefox-debugsource | 0:68.2.0-2.el8_0 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| red hat:jbcs-httpd24-curl | 0:7.64.1-36.jbcs.el6 · Red Hat:jboss_core_services:1::el6 | Package registry (OSV) |
| red hat:jbcs-httpd24-curl-debuginfo | 0:7.64.1-36.jbcs.el6 · Red Hat:jboss_core_services:1::el6 | Package registry (OSV) |
| red hat:jbcs-httpd24-httpd | 0:2.4.37-57.jbcs.el6 · Red Hat:jboss_core_services:1::el6 | Package registry (OSV) |
| red hat:jbcs-httpd24-httpd-debuginfo | 0:2.4.37-57.jbcs.el6 · Red Hat:jboss_core_services:1::el6 | Package registry (OSV) |
| red hat:jbcs-httpd24-httpd-devel | 0:2.4.37-57.jbcs.el6 · Red Hat:jboss_core_services:1::el6 | Package registry (OSV) |
| red hat:jbcs-httpd24-httpd-manual | 0:2.4.37-57.jbcs.el6 · Red Hat:jboss_core_services:1::el6 | Package registry (OSV) |
| red hat:thunderbird | 0:68.2.0-1.el7_7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:thunderbird-debuginfo | 0:68.2.0-1.el7_7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:thunderbird-debugsource | 0:68.2.0-1.el8_0 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| rocky linux:expat | 0:2.2.5-4.el8 · Rocky Linux:8 | Package registry (OSV) |
| suse:expat | 2.2.5-3.6.1 · SUSE:Linux Enterprise Module for Basesystem 15 | Package registry (OSV) |
| suse:MozillaFirefox | 68.2.0-3.59.1 · SUSE:Linux Enterprise Module for Desktop Applications 15 | Package registry (OSV) |
| suse:MozillaFirefox-branding-SLE | 68-4.11.2 · SUSE:Linux Enterprise Module for Desktop Applications 15 | Package registry (OSV) |
| suse:MozillaThunderbird | 68.2.1-3.58.1 · SUSE:Linux Enterprise Workstation Extension 15 | Package registry (OSV) |
| suse:python36 | 3.6.10-4.3.5 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:python36-base | 3.6.10-4.3.5 · SUSE:Linux Enterprise Server 12 SP5 | Package 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.
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 researchersFinders, 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).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-21-0196 · Mar 4, 2021(IBM Güvenlik Bülteni Yayınladı)
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
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-125 · Out-of-bounds ReadCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (19 more)Show less
- lists.opensuse.org/opensuse-security-announce/2019-09/msg00081.html
- lists.opensuse.org/opensuse-security-announce/2019-11/msg00000.html
- lists.opensuse.org/opensuse-security-announce/2019-11/msg00002.html
- lists.opensuse.org/opensuse-security-announce/2019-11/msg00003.html
- lists.opensuse.org/opensuse-security-announce/2019-11/msg00013.html
- lists.opensuse.org/opensuse-security-announce/2019-11/msg00016.html
- lists.opensuse.org/opensuse-security-announce/2019-11/msg00017.html
- lists.opensuse.org/opensuse-security-announce/2019-11/msg00018.html
- lists.opensuse.org/opensuse-security-announce/2019-11/msg00019.html
- lists.opensuse.org/opensuse-security-announce/2020-01/msg00008.html
- lists.opensuse.org/opensuse-security-announce/2020-01/msg00040.html
- packetstormsecurity.com/files/154503/Slackware-Security-Advisory-expat-Updates.html
- packetstormsecurity.com/files/154927/Slackware-Security-Advisory-python-Updates.html
- packetstormsecurity.com/files/154947/Slackware-Security-Advisory-mozilla-firefox-Updates.html
- seclists.org/fulldisclosure/2019/Dec/23
- seclists.org/fulldisclosure/2019/Dec/26
- seclists.org/fulldisclosure/2019/Dec/27
- seclists.org/fulldisclosure/2019/Dec/30
- access.redhat.com/errata/RHSA-2019:3210
Vendor advisories and official records. Exploit/PoC links are deliberately left out.