Security readout for executives and security teams
Plain-English summary
CVE-2026-25210 is an integer overflow issue in libexpat's XML parsing code before 2.7.4. A crafted local input could cause incorrect memory handling with potential confidentiality and integrity impact. The CVSS vector is local and high complexity, so urgency is moderate unless libexpat processes untrusted local files in sensitive workflows.
Executive priority
Schedule remediation through normal vulnerability management, with faster action for systems handling untrusted XML or sensitive data. No active exploitation is cited, but confidentiality and integrity impacts justify tracking and patching affected dependencies.
Technical view
The issue is CWE-190 in libexpat's doContent function. tag buffer reallocation does not properly check integer overflow when determining bufSize. The CVSS 3.1 score is 6.9: local attack vector, high attack complexity, no privileges, no user interaction, unchanged scope, high confidentiality and integrity impact, and low availability impact.
Likely exposure
Exposure is likely where applications, appliances, or embedded products include libexpat before 2.7.4 and parse XML from local or staged inputs. The source bundle names libexpat and references a Siemens advisory, but it does not enumerate affected Siemens products here.
Exploitation context
The provided sources do not show CISA KEV listing or active exploitation. The CVSS vector is local and high complexity, which limits broad remote exploitation assumptions. Treat this as a dependency risk until vendor advisories confirm exposure in deployed products.
Researcher notes
The public record is sparse in the bundle. The key technical clue is missing integer-overflow checking during tag buffer reallocation in doContent. Avoid assuming affected downstream products beyond referenced advisories unless vendor-specific evidence confirms bundling and vulnerable versions.
Mitigation direction
- Upgrade libexpat to 2.7.4 or later where directly managed.
- Track vendor advisories for products bundling libexpat.
- Prioritize systems parsing untrusted XML in sensitive workflows.
- Apply vendor-supplied updates for downstream appliances or software.
- If updates are unavailable, restrict untrusted XML processing where feasible.
Validation and detection
- Inventory applications and devices that bundle libexpat.
- Confirm deployed libexpat versions are 2.7.4 or later.
- Review SBOMs and vendor advisories for transitive exposure.
- Check whether XML inputs are local-only, staged, or user-controlled.
- Document compensating controls when vendor fixes are pending.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-190: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-25210 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.9 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L1.45.5mitreVulnerability scoring details
Base CVSS 3.1 score
6.9MediumVector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/libexpat/libexpat/pull/1075CVE reference, mitre
- https://github.com/libexpat/libexpat/pull/1075/commits/9c2d990389e6abe2e44527eeaa8b39f16fe859c7CVE reference, mitre
- https://cert-portal.siemens.com/productcert/html/ssa-253495.htmlCVE reference, siemens-SADP
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Integer Overflow or Wraparound
Integer Overflow or Wraparound represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.