CVE-2022-25235

xmltok_impl.c in Expat (aka libexpat) before 2.4.5 lacks certain validation of encoding, such as checks for whether a UTF-8 character is valid in a certain context.

Published: 2022-02-15 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-25235 is rated High Risk (66/100): CVSS Critical severity, with high exploitation likelihood (EPSS 4.92%, 91th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2022-25235

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 12.35% 4.92% -7.43%
2 2026-06-12 11.03% 12.35% +1.32%
3 2026-06-02 — 11.03% —

Full EPSS history (57 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-25235

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2022-25235

OS Trackers for CVE-2022-25235

vendor priority summary link
alpine — CVE-2022-25235: 1 source package rows (expat); 8 state rows across 8 repos (3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 8, open 0. https://security.alpinelinux.org/vuln/CVE-2022-25235
debian not yet assigned CVE-2022-25235 not yet assigned priority: Debian including 2 source packages (expat, libxmltok), 7 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5, open 2. https://security-tracker.debian.org/tracker/CVE-2022-25235
gentoo high CVE-2022-25235: 1 GLSA(s) (202209-24), 1 atom(s) (dev-libs/expat); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2022-25235
redhat high — https://access.redhat.com/security/cve/CVE-2022-25235
suse high CVE-2022-25235 severity important: SUSE including 399 source package names (0.0.17-1.1:libexpat1-2.4.4-150400.3.6.9, 0.1.6-1.2:libexpat1-2.4.4-150400.3.6.9, …), 964 product×package rows across 420 product lines (Container bci/bci-base-fips, Container bci/bci-init, … (420 product lines)): Fixed 796, Known Affected 168. https://www.suse.com/security/cve/CVE-2022-25235/
ubuntu high CVE-2022-25235 high priority: Ubuntu including 24 source packages (apache2, apr-util, …), 337 status rows across 15 suites (bionic, focal, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 92, DNE 87, ignored 63, needs-triage 58, released 30, needed 7. https://ubuntu.com/security/CVE-2022-25235

Affected software / configurations for CVE-2022-25235

Vendor Product Version Raw CPE
libexpat_project libexpat < 2.4.5 cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
fedoraproject fedora 35 cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
oracle http_server 12.2.1.3.0 cpe:2.3:a:oracle:http_server:12.2.1.3.0:*:*:*:*:*:*:*
oracle http_server 12.2.1.4.0 cpe:2.3:a:oracle:http_server:12.2.1.4.0:*:*:*:*:*:*:*
oracle zfs_storage_appliance_kit 8.8 cpe:2.3:a:oracle:zfs_storage_appliance_kit:8.8:*:*:*:*:*:*:*
siemens sinema_remote_connect_server < 3.1 cpe:2.3:a:siemens:sinema_remote_connect_server:*:*:*:*:*:*:*:*

References for CVE-2022-25235

URL Tags
http://www.openwall.com/lists/oss-security/2022/02/19/1 Mailing List Third Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-484086.pdf Third Party Advisory
https://github.com/libexpat/libexpat/pull/562 Patch Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/03/msg00007.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3UFRBA3UQVIQKXTBUQXDWQOVWNBKLERU/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y27XO3JMKAOMQZVPS3B4MJGEAHCZF5OM/
https://security.gentoo.org/glsa/202209-24 Third Party Advisory
https://security.netapp.com/advisory/ntap-20220303-0008/ Third Party Advisory
https://www.debian.org/security/2022/dsa-5085 Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.html Patch Third Party Advisory
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