CVE-2026-82759

What it is

Use of a One-Way Hash with a Predictable Salt vulnerability in team-alembic AshAuthentication allows readers of the audit store to recover the client IP addresses that the audit log add-on's :hash privacy mode is meant to pseudonymise. AshAuthentication.AddOn.AuditLog.IpPrivacy.hash_ip/1 computes a single unkeyed :crypto.hash(:sha256, salt <> ip) and truncates the result to 16 hexadecimal characters. The salt is read from the :audit_log_ip_salt or :secret application config keys, and falls back to the constant "default-salt-change-in-production" published in the library source when neither is set, with nothing warning that the default is in use. The IPv4 space is only 2^32 values and SHA-256 is fast, so the whole hash table is precomputable and every stored value maps back to its source address. Truncating to 16 characters does not help, and even a configured salt leaves the hash cheap enough to enumerate once it leaks. This issue affects ash_authentication: from 4.12.0 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14.

At a glance

Exploitability

Can be exploited locally on the machine with an admin-level account. Limited direct impact.

Exploit odds

0.1% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-09-17 14:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-18 18:16 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.1% in the next 30 days (EPSS).
• Severity: 1.8 LOW (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-09-17 14:17 UTC

Last modified

2026-09-18 18:16 UTC

Exploit probability

0.1% · EPSS, next 30 days

Weakness

CWE-760

Record status

Deferred

Attack profile CVSS 4.0 · 1.8

Attack vector

Local

Complexity

Low

Attack requirements

Present

Privileges needed

High

User interaction

None

Confidentiality

Low

Integrity

None

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-82759.md and follow it. Check whether this project is affected by CVE-2026-82759. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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