Exploitation evidence
Known exploited · CISA KEV listed
Added 2026-09-21. Ransomware campaign use: Unknown.
CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
CISA due date: 2026-09-24. This is the catalog’s deadline, not an assessment of your organization’s exposure.
KEV checked 13 Nov 2026, 00:20 Jerusalem · Original catalog ↗Reported products and versions
Zyxel / GS1900-48HPv2 firmware
Default status: unaffected
- affected: <= 2.90(ABTQ.1)C0
Zyxel / GS1900-8 firmware
Default status: unaffected
- affected: <= 2.90(AAHH.1)C0
Zyxel / GS1900-8HP firmware
Default status: unaffected
- affected: <= 2.90(AAHI.1)C0
Zyxel / GS1900-10HP firmware
Default status: unaffected
- affected: <= 2.90(AAZI.1)C0
Zyxel / GS1900-16 firmware
Default status: unaffected
- affected: <= 2.90(AAHJ.1)C0
Zyxel / GS1900-24 firmware
Default status: unaffected
- affected: <= 2.90(AAHL.1)C0
Zyxel / GS1900-24E firmware
Default status: unaffected
- affected: <= 2.90(AAHK.1)C0
Zyxel / GS1900-24EP firmware
Default status: unaffected
- affected: <= 2.90(ABTO.1)C0
Zyxel / GS1900-24HPv2 firmware
Default status: unaffected
- affected: <= 2.90(ABTP.1)C0
Zyxel / GS1900-48 firmware
Default status: unaffected
- affected: <= 2.90(AAHN.1)C0
Fixes and workarounds
No explicit solution text in the downloaded CVE record. Consult the vendor advisory; unaffected version ranges are shown above as reported, not inferred as a patch recommendation.
Sources and related reporting
CVE Program record ↗ · Download tracked evidence as JSON
- https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-stack-based-buffer-overflow-vulnerability-in-gs1900-series-switches-06-16-2026
- https://www.greynoise.io/blog/open-season-on-kapibala-attacker-steals-government-records-wordpress-exploitation
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-7273
Monitored source mentions
Shared CVE identifiers link source mentions; they do not establish that the reports describe the same incident.
Observed change timeline
History begins when Egret first downloads each source. It is not the complete upstream CVE history.
12 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-12",
"epss": 0.02734,
"percentile": 0.86312
}10 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-10",
"epss": 0.02734,
"percentile": 0.86227
}09 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-09",
"epss": 0.02734,
"percentile": 0.8621
}08 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-08",
"epss": 0.02734,
"percentile": 0.86202
}07 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-07",
"epss": 0.02734,
"percentile": 0.86192
}06 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-06",
"epss": 0.02734,
"percentile": 0.86172
}06 Nov 2026, 06:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-05",
"epss": 0.02778,
"percentile": 0.86421
}04 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-04",
"epss": 0.02778,
"percentile": 0.86408
}03 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-03",
"epss": 0.02778,
"percentile": 0.86386
}03 Nov 2026, 06:20 Jerusalem · CVE Program record changed
Stored CNA snapshot at this observation.
{
"containers": {
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"metrics": [
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"content": {
"id": "CVE-2026-7273",
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"timestamp": "2026-06-17T00:00:00+00:00",
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"url": "https://www.greynoise.io/blog/open-season-on-kapibala-attacker-steals-government-records-wordpress-exploitation"
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"tags": [
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"time": "2026-09-21T00:00:00.000Z",
"value": "CVE-2026-7273 added to CISA KEV"
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"title": "CISA ADP Vulnrichment"
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],
"cna": {
"affected": [
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"product": "GS1900-48HPv2 firmware",
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"product": "GS1900-24 firmware",
"vendor": "Zyxel",
"versions": [
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"version": "<= 2.90(AAHL.1)C0"
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{
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"product": "GS1900-24E firmware",
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"product": "GS1900-24EP firmware",
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"product": "GS1900-48 firmware",
"vendor": "Zyxel",
"versions": [
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"version": "<= 2.90(AAHN.1)C0"
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}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "ADJACENT_NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 8.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
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"problemTypes": [
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"descriptions": [
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"cweId": "CWE-121",
"description": "CWE-121 Stack-based buffer overflow",
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"providerMetadata": {
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"orgId": "96e50032-ad0d-4058-a115-4d2c13821f9f",
"shortName": "Zyxel"
},
"references": [
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"tags": [
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],
"url": "https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-stack-based-buffer-overflow-vulnerability-in-gs1900-series-switches-06-16-2026"
}
],
"source": {
"discovery": "UNKNOWN"
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"cveMetadata": {
"assignerOrgId": "96e50032-ad0d-4058-a115-4d2c13821f9f",
"assignerShortName": "Zyxel",
"cveId": "CVE-2026-7273",
"datePublished": "2026-06-16T02:20:29.847Z",
"dateReserved": "2026-04-28T06:21:36.574Z",
"dateUpdated": "2026-09-22T03:55:39.207Z",
"state": "PUBLISHED"
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"dataType": "CVE_RECORD",
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}03 Nov 2026, 02:22 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-02",
"epss": 0.02778,
"percentile": 0.86369
}03 Nov 2026, 02:22 Jerusalem · CISA KEV status changed
Stored KEV snapshot at this observation.
{
"cveID": "CVE-2026-7273",
"cwes": [
"CWE-121"
],
"dateAdded": "2026-09-21",
"dueDate": "2026-09-24",
"forensicTriage": "Yes",
"knownRansomwareCampaignUse": "Unknown",
"notes": "https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-stack-based-buffer-overflow-vulnerability-in-gs1900-series-switches-06-16-2026 ; ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-7273",
"product": "GS1900 Series Switches",
"requiredAction": "Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.",
"shortDescription": "Zyxel GS1900 series switches contain a stack-based buffer overflow vulnerability in the CGI program which could allow a LAN-based, unauthenticated attacker to exploit the flaw and potentially execute OS commands via a crafted HTTP request.",
"vendorProject": "Zyxel",
"vulnerabilityName": "Zyxel GS1900 Series Switches Stack-Based Buffer Overflow Vulnerability"
}