CVE-2026-76466

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A vulnerability in the database service feature of Cisco Expressway Series could allow an unauthenticated, remote attacker with network access to a Cisco Expressway device to execute arbitrary operating system commands as root. This vulnerability is due to the use of persistent cookies. Additionally, there is insufficient validation of client certificates when the TLS Verify Mode is set to Enabled for clustering, which means that client certificates are not validated. An attacker with possession of the cookies could exploit this vulnerability by connecting to the database service and invoking specific remote procedure call (RPC) commands. A successful exploit could allow the attacker to execute arbitrary commands as root on the underlying operating system of an affected device. Note: Cisco Expressway Series refers to Cisco Expressway Core (Expressway-C) devices and Cisco Expressway Edge (Expressway-E) devices.

CVSS 9.8 (CRITICAL)

Attention and evidence

HYPE SCORE

0.6/10

REALITY · THREAT PRIORITY

3.4/10

General review priority; not probability

Evidence confidence: Insufficient evidence

Why this priority?

Technical severity: CVSS 9.8: +3.43
Fresh EPSS: 0.42%: +0.01

General review priority, not probability, victim count or asset-specific risk. A range covers missing CVSS/EPSS inputs within the current evidence state.

Sources: 2 documents and public datasets.

Hype components

Headline sample (25%)

10/100

Press, 30 days (60%)

5/100

Grounded branding (15%)

0/100

HYPE TOTAL6/100

Sources and documents

Cisco Security Advisory

Technical advisory · 21 Oct 2026, 16:00 · Cisco Expressway Series Remote Code Execution Vulnerability

Cisco Security Advisory

Press · 21 Oct 2026, 16:00 · Cisco Expressway Series Remote Code Execution Vulnerability

Score evolution

● Hype ● Reality

Earlier evidence-support scores are retained in history; this chart shows only the current priority definition.

First record: hype 0.6 · reality 3.4 (2026-11-02 15:14). The curve appears once the score changes.

Public exploit evidence

Public exploit entries / repo candidates

Evidence context and dated references

Reality is general threat/review priority, combining observed exploitation, CVSS severity and fresh EPSS. Evidence confidence is separate. This is not calibrated risk, a victim count or an asset-specific assessment. A range reflects missing numeric inputs. Published 15 days ago. Exploitation evidence usually takes weeks to show up: a low reality score can mean there is no data yet, not that the flaw is mild.

Evidence in context

Confidence in exploitation evidence: Insufficient evidence
Priority basis: Exploitation in attacks unconfirmed; CVSS 9.8; EPSS 0.4%
Attention, last 30 days: 1 distinct story titles; 1 press documents; 1 publisher domains.
Technical potential: network access, no prior privileges, no user interaction.
Observed activity: No exploitation observation is recorded.
Known scale: Not quantified.
Evidence confidence basis: Insufficient evidence

Score evaluated: 2026-11-05 14:00:25.177862+00:00 · EPSS snapshot: 2026-11-05T12:03:04Z

Source event timeline

First press mention

21 Oct 2026, 16:00

Latest press mention

21 Oct 2026, 16:00

Published

21 Oct 2026, 16:14

Score calculated

05 Nov 2026, 14:00