accountsservice: Improper Neutralization of Special Elements used in an OS Command
CVE-2026-61898 is a high-severity improper neutralization of special elements used in an OS command vulnerability in accountsservice from Canonical, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 22.07.5-2ubuntu1.6, 23.13.9-2ubuntu6.1, 23.13.9-8ubuntu5.2 as the first without the flaw, so updating accountsservice to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.19% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update accountsservice to 22.07.5-2ubuntu1.6 or 23.13.9-2ubuntu6.1 or 23.13.9-8ubuntu5.2 or 23.13.9-8ubuntu7, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Canonical | accountsservice | 22.07.5-2ubuntu1 up to, but not including, 22.07.5-2ubuntu1.6; 23.13.9-2ubuntu6 up to, but not including, 23.13.9-2ubuntu6.1; 23.13.9-8ubuntu5 up to, but not including, 23.13.9-8ubuntu5.2; 23.13.9-8ubuntu6 up to, but not including, 23.13.9-8ubuntu7 | 22.07.5-2ubuntu1.6, 23.13.9-2ubuntu6.1, 23.13.9-8ubuntu5.2, 23.13.9-8ubuntu7 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (ubuntu.com).
Official description
The Ubuntu-specific language helper scripts (save-to-pam-env, update-langlist) shipped with accountsservice before 23.13.9-8ubuntu7 treat the user-controlled LANGUAGE entry in ~/.pam_environment as trusted input. The value is interpolated unescaped into a GNU sed replacement expression, allowing an attacker to inject a sed 'e' flag and arbitrary shell commands that execute with the privileges of the AccountsService helper process (real UID 0) via the SetLanguage D-Bus method.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements used in an OS Command
The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command before it is sent to a downstream component.
How developers prevent this class of flaw
- If at all possible, use library calls rather than external processes to recreate the desired functionality.
- For any data that will be used to generate a command to be executed, keep as much of that data out of external control as possible. For example, in web applications, this may require storing the data locally in the session's state instead of sending it out to the client in a hidden form field.
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
More Improper Neutralization of Special Elements used in an OS Command vulnerabilities (CWE-78)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in accountsservice
- 7.8 High severity
- 7.8 High severity
Recent Improper Neutralization of Special Elements used in an OS Command vulnerabilities
- 9.9 Critical severity
- 8.8 High severity
- 7.2 High severity
- 9.8 Critical severity
- 7.8 High severity
- 7.0 High severity
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