CVE-2026-6653Disclosure(xmlsoft / libxml2)

LOWCVSS 9.8 · CRITICAL

Exploit discussion active in current signal (1 latest mentions)

Immediate actions

Hunt for exploitation attempts and persistence artifacts
Increase monitoring for publicly documented tradecraft
Track advisory updates for patch or workaround availability

Recommended action window: High priority (within 72h)

NVD description

Use After Free in libxml2's xmlParseInternalSubset from GNOME libxml2 version 2.9.11 to 2.11.0 allows a remote attacker to cause a denial-of-service via maliciously crafted XML input with improper entity resolution handling.

xmlsoft CVEs Back to dashboard

1.5/ 10 priority

Sources & remediation

Patch / fix

https://gitlab.gnome.org/GNOME/libxml2/-/work_items/1058

Exploit / PoC references

Weakness type (CWE)

CWE-416CWE-611

Priority

LOW

Exploitation

NONE

PoC

YES

Patch

AVAILABLE

Momentum

STABLE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

libxml2

Threat summary

Public PoC is present in monitored signal
6 mentions across 4 observed days
Momentum state: stable

What's happening

PoC mentioned or linked in 1 signal
Technical details provided in 6 signals
Disclosure: 6 classified signals
Peaked 3d ago at 3 mentions (2026-06-22); latest day: 1
6 total mentions across 4 days

Affected systems

Vendors

xmlsoft

Products

libxml2

Deep dive

Activity timeline6 mentions / 4d

Signal classification1 categories

Disclosure

6100.0%

Referenced assets8 URLs

By indicator

Classification over time

Date	Total	Labels

2026-06-22	3	Disclosure3
2026-06-25	1	Disclosure1
2026-10-21	1	Disclosure1
2026-10-27	1	Disclosure1

Full discourse6 posts

zoomeyebot@zoomeyebot10d
Disclosure
🚨 libxml2 Use-After-Free in XML Internal Subset Parsing (CVE-2026-6653) Critical Vulnerability Alert! GNOME libxml2 2.9.11 before 2.11.0 is affected by CVE-2026-6653. 🔍 Identify Targets via ZoomEye: Search Dork: banner="libxml2" Exposure: 341 instances identified globally. ZoomEye Search Link: 👉 https://www.zoomeye.ai/searchResult?q=YmFubmVyPSJsaWJ4bWwyIg%3D%3D Read https://zoomeye.ai/agent.md and configure ZoomEye for this agent. #Infosec #CyberSecurity #ZoomEye
Post summary
The text announces a critical Use-After-Free vulnerability (CVE-2026-6653) affecting GNOME libxml2 versions before 2.11.0, highlighting 341 globally exposed instances via ZoomEye, and providing basic technical details without PoC, exploit, patch, or active exploitation information.
0000028
48 followersView on X
DuckButTurttle@DuckButTurttle16d
Disclosure
CISA published advisories for Hitachi Energy RTU500 (9 CVEs, top CVE-2026-6653, CVSS 8.8) and MicroSCADA X SYS600 (CVE-2026-9853, CVSS 7.8), both used in grid automation. No known exploitation. CISA https://www.cisa.gov/news-events/ics-advisories/icsa-26-293-05 #ICS
Post summary
CISA published advisories disclosing 9 CVEs affecting Hitachi Energy RTU500 and MicroSCADA X SYS600 in grid automation, with CVSS scores provided and no known exploitation reported. The primary focus is the announcement and initial technical details of these vulnerabilities.
0000020
9 followersView on X
Open Source Security mailing list@oss_security134d
Disclosure
CVE-2026-6653: libxml2: Use after free in xmlParseInternalSubset (>=2.9.11, <2.11.0) https://www.openwall.com/lists/oss-security/2026/06/22/3 due to improper entity resolution handling. A remote attacker could possibly use this issue to crash or possibly run arbitrary programs. PoC and reproduction instructions.
Post summary
This post announces the use‑after‑free vulnerability CVE‑2026‑6653 in libxml2, provides technical details and a PoC, but does not report active exploitation, a patch, or a false positive.
00000284
4.6K followersView on X
Infoflowcloud@infoflowcloud137d
Disclosure
🚨*CVE* CVE-2026-6653 Use After Free in libxml2's xmlParseInternalSubset from GNOME libxml2 version 2.9.11 to 2.11.0 allows a remote attacker to cause a denial-of-service via maliciously cra… https://www.cve.org/CVERecord?id=CVE-2026-6653 ----- Traducción: CVE-2026-6653 Use… http://infoflow.cloud`
Post summary
The post provides a brief disclosure of a use‑after‑free vulnerability in libxml2 that can cause denial of service, with no PoC, exploit tool, active exploitation claim, or patch information.
0000040
88 followersView on X
CVE@CVEnew137d
Disclosure
CVE-2026-6653 Use After Free in libxml2's xmlParseInternalSubset from GNOME libxml2 version 2.9.11 to 2.11.0 allows a remote attacker to cause a denial-of-service via maliciously cra… https://www.cve.org/CVERecord?id=CVE-2026-6653
Post summary
The tweet announces CVE-2026-6653, noting a use-after-free that causes a denial‑of‑service in libxml2, and links to the official CVE record.
00000707
57.7K followersView on X
Vulmon Vulnerability Feed@VulmonFeeds137d
Disclosure
CVE-2026-6653 Use After Free in GNOME libxml2 2.9.11 to 2.11.0 Denial-of-Service https://vulmon.com/vulnerabilitydetails?qid=CVE-2026-6653 Vulnerability Alert Subscriptions: https://alerts.vulmon.com/?utm_source=twitter&utm_medium=social&utm_campaign=2102281&utm_content=1
Post summary
This post announces the CVE‑2026‑6653 use‑after‑free vulnerability in GNOME libxml2 that can cause a denial‑of‑service, but it provides no proof‑of‑concepts, exploits, or patch information.
00000129
4.1K followersView on X

CPE platform detail1 entries

Part:

Vendor:

Product:

Version:

Target SW:

Target HW:

1 of 1 entries

Part	Vendor	Product	Version	Target SW	Target HW
App	xmlsoft	libxml2	-	-	-

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What researchers are saying

CVE-2026-6653

zoomeyebot[verified]@zoomeyebotDisclosure

The text announces a critical Use-After-Free vulnerability (CVE-2026-6653) affecting GNOME libxml2 versions before 2.11.0, highlighting 341 globally exposed instances via ZoomEye, and providing basic technical details without PoC, exploit, patch, or active exploitation information.

DuckButTurttle@DuckButTurttleDisclosure

CISA published advisories disclosing 9 CVEs affecting Hitachi Energy RTU500 and MicroSCADA X SYS600 in grid automation, with CVSS scores provided and no known exploitation reported. The primary focus is the announcement and initial technical details of these vulnerabilities.

Open Source Security mailing list@oss_securityDisclosure

This post announces the use‑after‑free vulnerability CVE‑2026‑6653 in libxml2, provides technical details and a PoC, but does not report active exploitation, a patch, or a false positive.

Infoflowcloud@infoflowcloudDisclosure

The post provides a brief disclosure of a use‑after‑free vulnerability in libxml2 that can cause denial of service, with no PoC, exploit tool, active exploitation claim, or patch information.

CVE@CVEnewDisclosure

The tweet announces CVE-2026-6653, noting a use-after-free that causes a denial‑of‑service in libxml2, and links to the official CVE record.

Vulmon Vulnerability Feed@VulmonFeedsDisclosure

This post announces the CVE‑2026‑6653 use‑after‑free vulnerability in GNOME libxml2 that can cause a denial‑of‑service, but it provides no proof‑of‑concepts, exploits, or patch information.