How severe is GHSA-8p34-64r3-mwg8?

No CVSS score has been assigned to GHSA-8p34-64r3-mwg8 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-8p34-64r3-mwg8?

GHSA-8p34-64r3-mwg8 affects the following packages: net-imap (RubyGems), net-imap (RubyGems). Ecosystems affected: RubyGems.

How do I fix GHSA-8p34-64r3-mwg8?

Update net-imap to 0.6.4.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8p34-64r3-mwg8 is resolved across your whole dependency graph.

How do I detect GHSA-8p34-64r3-mwg8 in my RubyGems dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for net-imap. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-8p34-64r3-mwg8 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-8p34-64r3-mwg8?

O3 pinpoints whether GHSA-8p34-64r3-mwg8 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-8p34-64r3-mwg8 actively exploited in the wild?

No public exploit code has been indexed for GHSA-8p34-64r3-mwg8 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-8p34-64r3-mwg8?

GHSA-8p34-64r3-mwg8 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 39th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-8p34-64r3-mwg8?

GHSA-8p34-64r3-mwg8 is classified as CWE-77 (CWE-77), CWE-93 (CWE-93). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-8p34-64r3-mwg8 published, and has it been updated?

GHSA-8p34-64r3-mwg8 was published on June 9, 2026 and was last updated on July 6, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

GHSA-8p34-64r3-mwg8: net-imap Command Injection

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk39th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

2 pkgs affected

💎net-imap💎net-imap

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.

Description

Several Net::IMAP commands accept a "raw data" argument that is sent verbatim after validation to prevent command injection. However, if a server does not support non-synchronizing literals, it may still be possible to inject arbitrary IMAP commands inside non-synchronizing literals.

Details

Raw data arguments support embedded literal values, both synchronizing and non-synchronizing. Non-synchronizing literals can only be safely sent when the server advertises any of the LITERAL+, LITERAL-, or IMAP4rev2 capabilities. But raw data arguments do not verify server support for non-synchronizing literals prior to sending.

Servers without support for non-synchronizing literals could handle them in several different ways: If a server sees a "}\r\n" byte sequence but can't parse the literal bytesize, it may cautiously decide to close the connection, blocking any command injection attacks. However, a server without support for non-synchronizing literals may instead interpret the "+}\r\n" as the end of a malformed command line and respond with a tagged BAD. In that case, the contents of the literal will be interpreted as one or more new pipelined commands, allowing a CRLF command injection attack to succeed.

This affects the following commands' string arguments:

criteria for #search and #uid_search
search_keys for #sort, #thread, #uid_sort, and #uid_thread
attr for #fetch and #uid_fetch

Prior to net-imap v0.6.4, v0.5.14, and v0.4.24, raw data arguments were not validated in any way, so they were also vulnerable to this attack. See CVE-2026-42257 (GHSA-hm49-wcqc-g2xg).

Impact

Fortunately, LITERAL- is supported by most modern IMAP servers. Even without support for non-synchronizing literals, cautious servers may handle invalid literal bytesize by closing the connection . However, servers which handle a non-synchronizing literal just like any other malformed command will enable this vulnerability.

If a developer passes an unvalidated user-controlled input for one of these method arguments, an attacker can append CRLF sequence followed by a new IMAP command (like DELETE mailbox). Although this does not directly enable data exfiltration, it could be combined with other attack vectors or knowledge of the target system's attributes, e.g.: shared mail folders or the application's installed response handlers.

Mitigation

Update to a version of net-imap which validates server support for non-synchronizing literals before sending them.

If upgrading net-imap is not possible:

Explicitly validate user-controlled inputs to prevent embedded non-synchronizing literals unless the server supports them.
For a simpler, more cautious approach: all embedded literals can be unconditionally prohibited, by checking that string inputs do not contain any CR or LF bytes.
Verify that the server advertises any of the LITERAL+, LITERAL-, or IMAP4rev2 capabilities before using untrusted string inputs for the affected "raw data" arguments.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
💎RubyGems	`net-imap`	≥ 0.6.0&&< 0.6.4.1	0.6.4.1
💎RubyGems	`net-imap`	all versions	0.5.15

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for net-imap. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update net-imap to 0.6.4.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8p34-64r3-mwg8 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-8p34-64r3-mwg8 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-8p34-64r3-mwg8. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Several Net::IMAP commands accept a "raw data" argument that is sent verbatim after validation to prevent command injection. However, if a server does not support non-synchronizing literals, it may still be possible to inject arbitrary IMAP commands inside non-synchronizing literals. ### Details Raw data arguments support embedded literal values, both synchronizing and non-synchronizing. Non-synchronizing literals can only be safely sent when the server advertises any of the `LITERAL+`, `LITERAL-`, or `IMAP4rev2` capabilities. But raw data arguments do not verify server support for non-sy

O3 Security · Impact-Aware SCA

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GHSA-8p34-64r3-mwg8