Vulnerability in SAP Approuter

CVE-2026-66776

SAP Approuter does not consistently enforce integrity verification on certain session-related request headers under specific conditions. An attacker with low privileges could send a specially crafted request that bypasses the integrity check and loads another user's session context. Successful exploitation requires the attacker to have previously observed matching session values out-of-band, which makes the attack complex to execute. This could result in a high impact on confidentiality and a low impact on integrity. There is no impact on availability.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (8.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 9th percentile — 8.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-66776: held from 0.001 to 0.002.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-66776?
CVE-2026-66776 is a medium-severity vulnerability in SAP Approuter, classified under Improper Verification of Cryptographic Signature. CVSS score: 5.9/10. Published 2026-08-11.
How severe is CVE-2026-66776?
Medium severity. CVSS v3 base score is 5.9 out of 10.