CVE-2025-52426
published 2026-01-02CVE-2025-52426: A NULL pointer dereference vulnerability has been reported to affect several QNAP operating system versions. If a remote attacker gains an administrator…
PriorityP425medium4.9CVSS 3.1
AVNACLPRHUINSUCNINAH
EPSS
0.30%
21.7th percentile
A NULL pointer dereference vulnerability has been reported to affect several QNAP operating system versions. If a remote attacker gains an administrator account, they can then exploit the vulnerability to launch a denial-of-service (DoS) attack.
We have already fixed the vulnerability in the following versions:
QTS 5.2.7.3256 build 20250913 and later
QuTS hero h5.2.7.3256 build 20250913 and later
QuTS hero h5.3.1.3250 build 20250912 and later
Affected
45 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| msrc | azl3_expat_2.5.0-1_on_azure_linux_3.0 | — | — |
| msrc | azl3_expat_2.6.2-1_on_azure_linux_3.0 | — | — |
| msrc | azure_linux_3.0_arm | — | — |
| msrc | azure_linux_3.0_x64 | — | — |
| msrc | cbl2_expat_2.5.0-1_on_cbl_mariner_2.0 | — | — |
| msrc | cbl2_expat_2.6.2-2_on_cbl_mariner_2.0 | — | — |
| msrc | cbl_mariner_2.0_arm | — | — |
| msrc | cbl_mariner_2.0_x64 | — | — |
| qnap | qts | — | — |
| qnap | qts | — | — |
| qnap | qts | — | — |
| qnap | qts | — | — |
| qnap | qts | — | — |
| qnap | qts | — | — |
| qnap | qts | — | — |
| qnap | qts | — | — |
| qnap | qts | — | — |
| qnap | qts | — | — |
| qnap | qts | — | — |
| qnap | qts | — | — |
| qnap | qts | — | — |
| qnap | qts | — | — |
| qnap | qts | — | — |
| qnap | qts | — | — |
| qnap | quts_hero | — | — |
CVSS provenance
nvdv3.14.9MEDIUMCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
nvdv4.01.2LOWCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
vendor_msrc5.5MEDIUM
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GHSA
GHSA-h65r-fq24-hw5g: A NULL pointer dereference vulnerability has been reported to affect several QNAP operating system versions
ghsa_unreviewed·2026-01-02
CVE-2025-52426 [LOW] CWE-476 GHSA-h65r-fq24-hw5g: A NULL pointer dereference vulnerability has been reported to affect several QNAP operating system versions
A NULL pointer dereference vulnerability has been reported to affect several QNAP operating system versions. If a remote attacker gains an administrator account, they can then exploit the vulnerability to launch a denial-of-service (DoS) attack.
We have already fixed the vulnerability in the following versions:
QTS 5.2.7.3256 build 20250913 and later
QuTS hero h5.2.7.3256 build 20250913 and later
QuTS hero h5.3.1.3250 build 20250912 and later
Microsoft
libexpat through 2.5.0 allows recursive XML Entity Expansion if XML_DTD is undefined at compile time.
vendor_msrc·2024-02-13·CVSS 5.5
CVE-2023-52426 [MEDIUM] CWE-776 libexpat through 2.5.0 allows recursive XML Entity Expansion if XML_DTD is undefined at compile time.
libexpat through 2.5.0 allows recursive XML Entity Expansion if XML_DTD is undefined at compile time.
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.
Mariner: Mariner
mitre: mitre
Customer Action Required: Yes
Remediation:
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2026-01-02
Published