Secuno
ENNL
Book demo

CVE-2026-42007

Use-after-free

9.1 CRITICALEPSS 0.34%
  1. Published28 Aug 2026

Description

An attacker that has valid credentials can use a Sieve script with the editheader extension to trigger a use-after-free in the mail editing code, and to write memory contents beyond the intended buffer into the delivered mail. This causes memory leak and opportunity to do memory corruption during mail delivery, which can crash the delivery process and may allow execution of arbitrary code in the context of that process. Disable the Sieve editheader extension. Update to non-vulnerable version. No publicly available exploits are known.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredLow
User interactionNone
ScopeChanged
ConfidentialityLow
IntegrityLow
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

CVE-2026-859658.0
Progress MarkLogic Server 12.x releases before 12.1.0 and 11.x releases before 11.3.7…
CVE-2026-57599.8
A double free and use-after-free vulnerability in the RdbLoadDeletedNodes function of…
CVE-2026-1071838.1
llama.cpp before b11393 contains a use-after-free and double free vulnerability in…
CVE-2026-553309.8
In BluetoothCccHandlerCallbackImpl of bluetooth_ccc.cc, there is a possible…
CVE-2026-1064238.8
Use after free in Media in Google Chrome prior to 155.0.8059.39 allowed a remote…
CVE-2026-1064218.8
Use after free in PDF in Google Chrome prior to 155.0.8059.39 allowed a remote attacker…

Frequently asked

Is CVE-2026-42007 being actively exploited?

CVE-2026-42007 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.34%.

How severe is CVE-2026-42007?

CVE-2026-42007 has a CVSS 3.1 base score of 9.1, rated critical. EPSS estimates a 0.34% probability of exploitation.

How do I fix CVE-2026-42007?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-42007 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation worksBook a demo

Get Patch this first every Monday

Five vulnerabilities that matter this week, ranked on real exploitation. Plain language, one email, no spam.

You can unsubscribe with one click from every issue. We handle your details as described in our privacy policy.

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.