Session fixation in the CLI login flow allows an unauthenticated attacker to obtain a user's API token
Affects nerves_hub_web from 2.5.0 before 2.5.3 where the CLI login flow (POST /api/auth/cli_session) is in use. Fixed in 2.5.3.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 2.5.3
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Affects nerves_hub from 2.5.0 before 2.5.3 The CLI login flow (POST /api/auth/cli_session) is in use and a signed-in user must open the returned confirmation URL and click Confirm
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 21/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The Nerves Hub web application (nerves_hub) has a session fixation flaw in its CLI login flow that lets an attacker obtain a user's API token. It can be reached remotely without logging in, but the victim must open a crafted login link and click Confirm.
Read the original description
Session Fixation vulnerability in the CLI login flow in nerves-hub nerves_hub_web allows an unauthenticated attacker to obtain an API token for another user's account via a crafted login link. Starting a CLI login with POST /api/auth/cli_session needs no authentication and returns a polling token, a confirmation URL that carries that token, and a confirmation code. When a signed-in user opens that URL and clicks Confirm, NervesHub.Accounts.verify_cli_session_token/2 creates an API token for the user's account and stores it on the login, and the next poll of GET /api/auth/cli_session/<token> returns it to whoever started the login.
The confirmation code is only displayed and is never compared with anything, so it cannot show that the person confirming is the one who started the login. The confirm form carries a CSRF token and the page cannot be framed, so the attacker has to persuade the user to open the link and click the button themselves.
This issue affects nerves_hub: from 2.5.0 before 2.5.3.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure12/25Specific setups only, reachable over the network without a login
- Reach?/20Unknown. No tracked technology or package matched
- Severity9.4/10CVSS 9.4
- No patch0/5No signal
What would change the score
- Would score about 71 if added to CISA KEV
- Would score about 66 if CISA's SSVC rates exploitation active
What to do
Check whether your setup matches what the bug needs.
Affects nerves_hub from 2.5.0 before 2.5.3 The CLI login flow (POST /api/auth/cli_session) is in use and a signed-in user must open the returned confirmation URL and click ConfirmUpgrade to a fixed version: 2.5.3.
Workaround: Block POST /api/auth/cli_session at the reverse proxy until the upgrade
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-119446 (Session fixation in the CLI login flow allows an unauthenticated attacker to obtain a user's API token), using the cve.now data below. Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only. What cve.now has for CVE-2026-119446 (entry last updated 2026-11-10): Affected: - nerves-hub nerves_hub_web: from 2.5.0, fixed in 2.5.3 - nerves-hub nerves_hub_web: from 2.5.0, fixed in 2.5.3 - nerves-hub nerves_hub_web: version range not reported Fixed versions: 2.5.3. Conditions (all must be true for the bug to be hit): - Affects nerves_hub from 2.5.0 before 2.5.3 (source: https://cna.erlef.org/cves/CVE-2026-119446.html) - The CLI login flow (POST /api/auth/cli_session) is in use and a signed-in user must open the returned confirmation URL and click Confirm (source: https://cna.erlef.org/cves/CVE-2026-119446.html) Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory. Attacker needs: network access, no login, a user action. Workaround: Block POST /api/auth/cli_session at the reverse proxy until the upgrade (source: https://github.com/nerves-hub/nerves_hub_web/security/advisories/GHSA-9vr9-463q-46qp) CISA KEV: CVE-2026-119446 is not listed as of cve.now's last read. This KEV status is for CVE-2026-119446 only. If you also check another CVE, look up its own KEV status; never assume it from this one. How to check: - Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory. Verify against the linked advisories before concluding, and cite the date you read each one: - https://github.com/nerves-hub/nerves_hub_web/security/advisories/GHSA-9vr9-463q-46qp - https://github.com/nerves-hub/nerves_hub_web/commit/3131f1701194b581ab4b3e5e9d81194fc9c83508 - https://cna.erlef.org/cves/CVE-2026-119446.html - https://osv.dev/vulnerability/EEF-CVE-2026-119446 - https://github.com/nerves-hub/nerves_hub_web/commit/e6bf11a812d7aa8b69d854ba8ef02d65516f5564 Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing. Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action. Entry: https://cve.now/CVE-2026-119446 For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-119446.
Timeline
- CVE published
- First seen by cve.now
- Posted on X by cve.now
- Record last updated
Affected versions
- nerves-hub/nerves-hub
From 2.5.0 · fixed in 2.5.3
- nerves_hub
From 2.5.0 · fixed in 2.5.3
- nerves-hub/nerves_hub_web
Version range not reported
Evidence 7
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Advisory
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-119446
Is CVE-2026-119446 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
The CLI login flow can be abused so that an unauthenticated attacker obtains an API token for another user's account via a crafted login link. When a signed-in user opens that link and clicks Confirm, the attacker can act as that user through the API.Source: cna.erlef.org, github.com
Which versions are affected by CVE-2026-119446?
nerves-hub/nerves-hub: from 2.5.0 before 2.5.3. nerves_hub: from 2.5.0 before 2.5.3.Source: cve.now feed data
Am I affected, and how do I check?
Versions from 2.5.0 before 2.5.3 of nerves_hub_web are affected, and only where the CLI login flow (POST /api/auth/cli_session) is in use. Check the installed nerves_hub_web version and whether the CLI login flow is enabled in your deployment.Source: cna.erlef.org, github.com
How do I fix CVE-2026-119446?
Upgrade nerves_hub_web to 2.5.3, which contains the fix. Until the upgrade is done, block POST /api/auth/cli_session at the reverse proxy.Source: cna.erlef.org, github.com