CVE-2025-438576.0MediumCWE-789

CVE-2025-43857: net-imap rubygem vulnerable to possible DoS by memory exhaustion

ruby · net-imap

Affected: ruby net-imap · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.5%probability of exploitation in the next 30 days

42nd percentile

050100

Higher than 42% of scored CVEs

6.0MediumCVSS 4.0

LowMediumHighCrit.

DescriptionCVE.org

Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.5.7, 0.4.20, 0.3.9, and 0.2.5, there is a possibility for denial of service by memory exhaustion when net-imap reads server responses. At any time while the client is connected, a malicious server can send can send a "literal" byte count, which is automatically read by the client's receiver thread. The response reader immediately allocates memory for the number of bytes indicated by the server response. This should not be an issue when securely connecting to trusted IMAP servers that are well-behaved. It can affect insecure connections and buggy, untrusted, or compromised servers (for example, connecting to a user supplied hostname). This issue has been patched in versions 0.5.7, 0.4.20, 0.3.9, and 0.2.5.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

ruby · net-imap>= 0.5.0, < 0.5.7; >= 0.4.0, < 0.4.20; >= 0.3.0, < 0.3.9; >= 0, < 0.2.5

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas

Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Memory Allocation with Excessive Size Value · Denial of Service
Vendor: ruby
Published: April 2025
Band: Unlikely (under 1%), April 2025

CoverageNo articles yet

No CyberSIXT article names CVE-2025-43857 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.