How severe is CVE-2026-66778?

CVE-2026-66778 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2026-66778 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-66778?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2026-66778 published?

CVE-2026-66778 was published on 2026-08-11.

CVE-2026-66778

CVE-2026-66778 is a medium-severity vulnerability with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-644.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 0% (15th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-644
Published: 2026-08-11
Last modified: 2026-08-11

Description

SAP Approuter does not sufficiently sanitize certain request headers before forwarding traffic to internal components. An unauthenticated attacker could send a specially crafted request to obtain limited unauthorized access to information. This results in a low impact on confidentiality. There is no impact on integrity and availability.

Frequently asked questions

What is CVE-2026-66778?: SAP Approuter does not sufficiently sanitize certain request headers before forwarding traffic to internal components. An unauthenticated attacker could send a specially crafted request to obtain limited unauthorized access to information. This results in a low impact on confidentiality. There is no impact on integrity and availability.
How severe is CVE-2026-66778?: CVE-2026-66778 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2026-66778 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-66778?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-66778 published?: CVE-2026-66778 was published on 2026-08-11.

References

Other CWE-644 vulnerabilities

CVE-2025-70948 — Critical (CVSS 9.3): A host header injection vulnerability in the mailer component of @perfood/couch-auth v0.26.0 allows attackers to obtain…
CVE-2026-26747 — Critical (CVSS 9.1): A Host Header Poisoning vulnerability exists in Monica 4.1.2 due to improper handling of the HTTP Host header in…
CVE-2026-26234 — High (CVSS 8.8): JUNG Smart Visu Server 1.1.1050 contains a request header manipulation vulnerability that allows unauthenticated…
CVE-2023-32465 — High (CVSS 8.8): Dell Power Protect Cyber Recovery, contains an Authentication Bypass vulnerability. An attacker could potentially…
CVE-2026-33805 — High (CVSS 8.6): @fastify/reply-from v12.6.1 and earlier and @fastify/http-proxy v11.4.3 and earlier process the client's Connection…
CVE-2025-64484 — High (CVSS 8.5): OAuth2-Proxy is an open-source tool that can act as either a standalone reverse proxy or a middleware component…

Browse all CWE-644 vulnerabilities →