CVE-2026-31248: n/a
Docling's METS GBS backend is vulnerable to XML Entity Expansion (XXE) attacks thru 2.61.0. The backend extracts and validates XML files from .tar.gz archives using etree.fromstring() without disabling entity resolution. An attacker can craft a malicious XML file with nested entity definitions (XML Bomb) and package it into a .tar.gz archive. When processed by Docling, the exponential expansion of entities during XML parsing leads to excessive resource consumption, resulting in a denial of service (DoS) condition on the system running the Docling parser.
AI Analysis
Technical Summary
The vulnerability CVE-2026-31248 affects Docling's METS GBS backend through version 2.61.0. It is caused by the use of etree.fromstring() for XML parsing without disabling entity resolution, allowing an attacker to submit a malicious XML file with nested entity definitions (XML bomb) inside a .tar.gz archive. When processed, the exponential expansion of these entities leads to excessive CPU and memory usage, causing a denial of service condition. The vulnerability is classified under CWE-776 (Improper Restriction of Recursive Entity References in DTDs). The CVSS v3.1 base score is 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), indicating a network exploitable vulnerability with no confidentiality or integrity impact but high impact on availability. There is no vendor advisory or patch information available at this time.
Potential Impact
Successful exploitation results in a denial of service condition due to resource exhaustion caused by XML entity expansion during parsing. There is no impact on confidentiality or integrity. The system running the Docling parser may become unresponsive or crash, disrupting service availability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, users should consider implementing XML parsing configurations that disable entity resolution or use safer XML parsing libraries. Additionally, validating and sanitizing input archives before processing may help reduce risk. Monitor vendor channels for official patches or updates.
CVE-2026-31248: n/a
Description
Docling's METS GBS backend is vulnerable to XML Entity Expansion (XXE) attacks thru 2.61.0. The backend extracts and validates XML files from .tar.gz archives using etree.fromstring() without disabling entity resolution. An attacker can craft a malicious XML file with nested entity definitions (XML Bomb) and package it into a .tar.gz archive. When processed by Docling, the exponential expansion of entities during XML parsing leads to excessive resource consumption, resulting in a denial of service (DoS) condition on the system running the Docling parser.
CVSS v3.1
Score 7.5high
Affected software
pkg:github/docling-project/doclingRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-31248 affects Docling's METS GBS backend through version 2.61.0. It is caused by the use of etree.fromstring() for XML parsing without disabling entity resolution, allowing an attacker to submit a malicious XML file with nested entity definitions (XML bomb) inside a .tar.gz archive. When processed, the exponential expansion of these entities leads to excessive CPU and memory usage, causing a denial of service condition. The vulnerability is classified under CWE-776 (Improper Restriction of Recursive Entity References in DTDs). The CVSS v3.1 base score is 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), indicating a network exploitable vulnerability with no confidentiality or integrity impact but high impact on availability. There is no vendor advisory or patch information available at this time.
Potential Impact
Successful exploitation results in a denial of service condition due to resource exhaustion caused by XML entity expansion during parsing. There is no impact on confidentiality or integrity. The system running the Docling parser may become unresponsive or crash, disrupting service availability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, users should consider implementing XML parsing configurations that disable entity resolution or use safer XML parsing libraries. Additionally, validating and sanitizing input archives before processing may help reduce risk. Monitor vendor channels for official patches or updates.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mitre
- Date Reserved
- 2026-03-09T00:00:00.000Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a028781cbff5d86108b8f60
Added to database: 05/12/2026, 01:50:57 UTC
Last enriched: 05/19/2026, 10:30:34 UTC
Last updated: 07/06/2026, 08:51:18 UTC
Views: 107
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