CVE-2025-11847: A null pointer dereference vulnerability in the IP settings CGI program of the Zyxel VMG3625-T50B firmware ver
37
Routine
MEDIUM 4.9MITIGATEMITIGATEMITIGATE
CVE-2025-11847 is a medium-severity flaw (CVSS 4.9) affecting ex3510-b1 firmware, ex3600-t0 firmware, ex5401-b1 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
A null pointer dereference vulnerability in the IP settings CGI program of the Zyxel VMG3625-T50B firmware versions through 5.50(ABPM.9.6)C0 and the Zyxel WX3100-T0 firmware versions through 5.50(ABVL.4.8)C0 could allow an authenticated attacker with administrator privileges to trigger a denial-of-service (DoS) condition by sending a crafted HTTP request.
Why this priority
No elevated risk signals yet
No fix is published yet: follow the downgrade or mitigation steps.
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
Published CVE record published
Updated Record last modified
zyxel ex3510-b1 firmware MITIGATE
Affected: < 5.17\(abup.15.2\)c0
Fixed in: 5.17\(abup.15.2\)c0
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
zyxel ex3600-t0 firmware MITIGATE
Affected: < 5.70\(acif.2.1\)c0
Fixed in: 5.70\(acif.2.1\)c0
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
zyxel ex5401-b1 firmware MITIGATE
Affected: < 5.17\(abyo.7.1\)c0
Fixed in: 5.17\(abyo.7.1\)c0
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
zyxel ex5510-b0 firmware MITIGATE
Affected: < 5.17\(abqx.11.1\)c0
Fixed in: 5.17\(abqx.11.1\)c0
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
zyxel ex5512-t0 firmware MITIGATE
Affected: < 5.70\(aceg.5.3\)c0
Fixed in: 5.70\(aceg.5.3\)c0
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
zyxel ex5601-t0 firmware MITIGATE
Affected: < 5.70\(acdz.5.1\)c0
Fixed in: 5.70\(acdz.5.1\)c0
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
Verify at the official sourceNVD · CVE Program · Report a problem with this page Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2025-11847?
ex3510-b1 firmware: mitigate or apply the listed mitigation; ex3600-t0 firmware: mitigate or apply the listed mitigation; ex5401-b1 firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2025-11847 being exploited?
CVE-2025-11847 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2025-11847 affect?
CVE-2025-11847 affects ex3510-b1 firmware, ex3600-t0 firmware, ex5401-b1 firmware. Severity is medium (CVSS 4.9). A null pointer dereference vulnerability in the IP settings CGI program of the Zyxel VMG3625-T50B firmware versions through 5.50(ABPM.9.6)C0 and the Zyxel WX3100-T0 firmware versions through 5.50(ABVL.4.8)C0 could allow an authenticated att
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