How severe is CVE-2026-94056?

CVE-2026-94056 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability low.

Is CVE-2026-94056 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-94056?

CVE-2026-94056 affects Exim. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-94056?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-94056 published?

CVE-2026-94056 was published on 2026-09-19 and last updated on 2026-09-24.

CVE-2026-94056

CVE-2026-94056 is a high-severity vulnerability in Exim with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-908.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (14th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-908
Affected product: Exim
Published: 2026-09-19
Last modified: 2026-09-24

Description

Exim before 4.100.1, when Proxy-Protocol is used with an attacker-controlled proxy, allows attackers to read certain uninitialized data from stack memory.

Frequently asked questions

What is CVE-2026-94056?: Exim before 4.100.1, when Proxy-Protocol is used with an attacker-controlled proxy, allows attackers to read certain uninitialized data from stack memory.
How severe is CVE-2026-94056?: CVE-2026-94056 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability low.
Is CVE-2026-94056 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-94056?: CVE-2026-94056 affects Exim. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-94056?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-94056 published?: CVE-2026-94056 was published on 2026-09-19 and last updated on 2026-09-24.

References

https://lists.exim.org/lurker/message/20260918.121220.0f87338e.en.html

Affected products (1)

cpe:2.3:a:exim:exim:*:*:*:*:*:*:*:*

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All CVEs affecting Exim →

Other CWE-908 (Use of Uninitialized Resource) vulnerabilities

CVE-2025-38429 — Critical (CVSS 10.0): In the Linux kernel, the following vulnerability has been resolved: bus: mhi: ep: Update read pointer only after…
CVE-2026-56190 — Critical (CVSS 9.8): Use of uninitialized resource in Windows RDP allows an unauthorized attacker to execute code over a network.
CVE-2026-52989 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: propagate nvmet_tcp_build_pdu_iovec()…
CVE-2022-50335 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: 9p: set req refcount to zero to avoid…
CVE-2025-38737 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: cifs: Fix oops due to uninitialised variable Fix…
CVE-2025-38472 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack: fix crash due to removal…

Browse all CWE-908 (Use of Uninitialized Resource) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

64.23.143.231 (ipv4-addr)
103.212.120.214 (ipv4-addr)
103.24.12.154 (ipv4-addr)
182.160.155.166 (ipv4-addr)
23.235.194.34 (ipv4-addr)
113.197.39.61 (ipv4-addr)
67.43.6.125 (ipv4-addr)
67.43.15.13 (ipv4-addr)