What is the CVSS score of CVE-2026-24515?

CVE-2026-24515 has a CVSS 3.1 base score of 2.9 (Low). CVSS vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L. EPSS exploitation probability: 0.0%.

How to fix or mitigate CVE-2026-24515?

During next maintenance window: Apply vendor patches when convenient. Verify null pointer dereference controls are in place.

Libexpat CVE-2026-24515

LOW

NULL Pointer Dereference (CWE-476)

2026-01-23 cve@mitre.org

Denial Of Service Null Pointer Dereference Libexpat Libexpat Project

2.9

CVSS 3.1 · NVD

View

Vulnerability Assessment

Weakness	CWE CWE-476 OWASP Top 10:2025 A06:2021 - Vulnerable and Outdated Components ASVS 5.0 V14 - Configuration Dependency management, component inventory MITRE ATT&CK 1 technique across 1 tactic: Impact The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Impact	CVSS 2.9 (LOW). Attack vector: Local. Complexity: High. Privileges required: None. User interaction: None.
Exploit ScenarioDerived	An attacker could exploit this vulnerability to compromise the affected system.

Monitor Track and reassess. Why: LOW severity (CVSS 0.1-3.9).

No patch listed yet 0.0% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Mar 12, 2026

In libexpat before 2.7.4, XML_ExternalEntityParserCreate does not copy unknown encoding handler user data. [CVSS 2.9 LOW]

RemediationAI

Monitor vendor advisories for a patch.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Classified as CWE-476 (NULL Pointer Dereference). Affects Libexpat. In libexpat before 2.7.4, XML_ExternalEntityParserCreate does not copy unknown encoding handler user data.

Know when Libexpat gets its next vulnerability

Watch products and get an email when something new is published
Check this CVE against your own stack and servers
Exploit and PoC references, threat intelligence from 22 sources

Continue with Google Continue with GitHub

No credit card · 7-day full trial

Severity by source

NVD PRIMARY 2.9 LOW

AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Local

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

Low

DescriptionCVE.org

In libexpat before 2.7.4, XML_ExternalEntityParserCreate does not copy unknown encoding handler user data.

Executive ViewAI

Why It Matters

CVE-2026-24515 is a low-severity vulnerability in libexpat involving null pointer dereference (CVSS 2.9). The limited severity suggests constrained impact, typically requiring specific conditions or local access for exploitation. Apply vendor updates when available as part of routine maintenance.

Business Impact: Low

Compensating Controls

Apply vendor patch during routine maintenance. Standard null pointer dereference mitigations apply if patching is delayed.

Threat Intelligence Overview

EPSS Score

0.0%

Top 100% exploitable

Threat Intel

1 source

Data Quality

4 sources

Confidence: Medium

NVD

CVE.org

EPSS CISA

GitHub

VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity LOW

CISA KEV No

Public POC No

EPSS 0.0%

Patch available No

Active threat Yes

Deciding rule

LOW severity (CVSS 0.1-3.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Defer

Exploitation· derived

None

System Exposure· derived

Small

Automatable· derived

Human Impact

Low

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +14

PoC: 0

Weaponized: 0

Threat intel: +10

Gov advisory: 0

Attack Technique

Null Pointer Dereference MEDIUM

A null pointer dereference occurs when a program attempts to access memory through a pointer that has been set to NULL (address 0x0).

Denial of Service MEDIUM

Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.

Affected Products (CPE)CVE.org

cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*

More in Libexpat

View all

CVE-2022-25315 CRITICAL Act Now POC

9.8 Feb 18

In Expat (aka libexpat) before 2.4.5, there is an integer overflow in storeRawNames. Rated critical severity (CVSS 9.8),

CVE-2025-59375 HIGH Act Now POC

7.5 Sep 15

libexpat in Expat before 2.7.2 allows attackers to trigger large dynamic memory allocations via a small document that is

CVE-2019-15903 HIGH This Week POC

7.5 Sep 04

In libexpat before 2.2.8, crafted XML input could fool the parser into changing from DTD parsing to document parsing too

CVE-2026-115506 HIGH This Week POC

8.7 Oct 22

CPU exhaustion in libexpat through 2.9.0 lets remote attackers stall XML parsing workloads by supplying a moderately siz

CVE-2026-93990 HIGH This Week POC

8.7 Sep 19

Malformed UTF-16 decoding in libexpat through 2.8.4 lets remote attackers hide XML markup from the parser: a lone high s

CVE-2022-43680 HIGH This Week POC

7.5 Oct 24

In libexpat through 2.4.9, there is a use-after free caused by overeager destruction of a shared DTD in XML_ExternalEnti

CVE-2024-28757 HIGH This Week POC

7.5

Alpine Linux: expat fixed in 2.6.2-r0

CVE-2017-9233 HIGH This Week POC

7.5 Jul 25

XML External Entity vulnerability in libexpat 2.2.0 and earlier (Expat XML Parser Library) allows attackers to put the p

CVE-2026-45186 HIGH This Week POC

7.5 May 10

Denial of service in libexpat before 2.8.1 lets remote attackers exhaust CPU by submitting moderately sized crafted XML

CVE-2013-0340 MEDIUM This Month POC

6.8 Jan 21

expat before version 2.4.0 does not properly handle entities expansion unless an application developer uses the XML_SetE

CVE-2016-0718 CRITICAL Act Now

9.8 May 26

Expat allows context-dependent attackers to cause a denial of service (crash) or possibly execute arbitrary code via a m

CVE-2024-45492 CRITICAL Act Now

9.8 Aug 30

An issue was discovered in libexpat before 2.6.3. Rated critical severity (CVSS 9.8), this vulnerability is remotely exp

Same weakness CWE-476 – NULL Pointer Dereference

View all

CVE-2016-0742 HIGH

7.5

CVE-2014-3470 MEDIUM

4.3

CVE-2020-1967 HIGH POC

7.5

CVE-2017-3730 HIGH POC

7.5

CVE-2017-3169 CRITICAL POC

9.8

CVE-2016-4957 HIGH

7.5

CVE-2021-3449 MEDIUM

5.9

CVE-2015-3194 HIGH

7.5

Same technique Denial Of Service

View all

CVE-2015-5119 CRITICAL POC

9.8

CVE-2011-2462 CRITICAL POC

9.8

CVE-2011-0611 HIGH POC

8.8

CVE-2012-1889 HIGH POC

8.8

CVE-2012-0507 CRITICAL POC

9.8

CVE-2014-1761 HIGH POC

7.8

CVE-2015-5122 CRITICAL POC

9.8

CVE-2011-0609 HIGH POC

7.8

Threat IntelligenceMISP

CISA Advisories

ICSA-26-155-04 ICSA-26-188-05

Sources: CISA (public domain)

References

Advisories & patches

ADVISORY https://vuldb.com/vuln/342529 REF https://cert-portal.siemens.com/productcert/html/ssa-253495.html REF https://github.com/libexpat/libexpat/pull/1131

Search Externally

GitHub PoC

Exploit-DB PacketStorm Snyk Rapid7 Nuclei Templates Trickest PoC

Back