docker-mailbox: Improper Neutralization of CRLF Sequences
CVE-2026-82973 is a critical-severity improper neutralization of CRLF sequences vulnerability in docker-mailbox from Psyb0t, with a CVSS 3.1 base score of 9.4 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected docker-mailbox versions: 0.1.0 through 0.4.12. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.42% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of docker-mailbox you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Psyb0t | docker-mailbox | 0.1.0 through 0.4.12 | Not stated |
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
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- LowSome restricted data 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:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H. Scored by CNA (gitlab.com).
Official description
Improper neutralization of CRLF sequences in IMAP command construction in psyb0t/docker-mailbox before 0.4.13 allows a remote unauthenticated attacker, when bearer-token authentication is not configured, to inject additional IMAP commands into an authenticated upstream mailbox connection via crafted folder, UID, or search values.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of CRLF Sequences
The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs.
How developers prevent this class of flaw
- Appropriately filter or quote CRLF sequences in user-controlled input.
More Improper Neutralization of CRLF Sequences vulnerabilities (CWE-93)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
References
Patches and release notes
Recent Improper Neutralization of CRLF Sequences vulnerabilities
- 9.9 Critical severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.2 High severity
- 8.8 High severity
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