CVE-2026-25210

In libexpat before 2.7.4, the doContent function does not properly determine the buffer size bufSize because there is no integer overflow check for tag buffer reallocation.

Published: 2026-01-30 Last update: 2026-06-02 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-25210 is rated Low Risk (27.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.01%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2026-25210

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 2026-01-30 — 0.01% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-25210

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.9 3.1 MEDIUM
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 1.4 5.5 [email protected]
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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:L)
A normal user session is enough; they don’t have to be admin.
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.
 1.8 5.9 [email protected]

Weakness enumeration for CVE-2026-25210

GitHub Security Advisory for CVE-2026-25210

GHSA-857q-6v86-xp84 · Severity: medium — In libexpat before 2.7.4, the doContent function does not properly determine the buffer size...

OS Trackers for CVE-2026-25210

vendor priority summary link
alpine — CVE-2026-25210: 1 source package rows (expat); 5 state rows across 5 repos (3.20-main, 3.21-main, 3.22-main, 3.23-main, edge-main); fixed 5, open 0. https://security.alpinelinux.org/vuln/CVE-2026-25210
debian not yet assigned CVE-2026-25210 not yet assigned priority: Debian including 1 source packages (expat), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. https://security-tracker.debian.org/tracker/CVE-2026-25210
redhat medium — https://access.redhat.com/security/cve/CVE-2026-25210
suse medium CVE-2026-25210 severity moderate: SUSE including 279 source package names (1.1.1-1.31:libexpat1-2.7.1-150700.3.9.2, 1.1.1-1.32:libexpat1-2.7.1-150700.3.9.2, …), 414 product×package rows across 128 product lines (Container private-registry/harbor-portal, Container private-registry/harbor-trivy-adapter, … (128 product lines)): Known Affected 231, Fixed 180, First Fixed 3. https://www.suse.com/security/cve/CVE-2026-25210/
ubuntu medium CVE-2026-25210 medium priority: Ubuntu including 23 source packages (apache2, apr-util, …), 155 status rows across 8 suites (bionic, focal, jammy, noble, questing, trusty, upstream, xenial): needs-triage 73, not-affected 47, DNE 18, released 13, ignored 4. https://ubuntu.com/security/CVE-2026-25210

Affected software / configurations for CVE-2026-25210

Vendor Product Version Raw CPE
libexpat_project libexpat < 2.7.4 cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*

References for CVE-2026-25210

cvelogic Threat Intelligence