How severe is CVE-2026-94054?

CVE-2026-94054 has a CVSS 3.x base score of 7.0, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability low.

Is CVE-2026-94054 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-94054?

CVE-2026-94054 affects Exim. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-94054?

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-2026-94054 published?

CVE-2026-94054 was published on 2026-09-19 and last updated on 2026-09-24.

CVE-2026-94054

CVE-2026-94054 is a high-severity vulnerability in Exim with a CVSS 3.x base score of 7.0. 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-787.

Key facts

Severity: High (CVSS 3.x base score 7.0)
EPSS exploit prediction: 0% (17th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
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, has an out-of-bounds write.

Frequently asked questions

What is CVE-2026-94054?: Exim before 4.100.1, when Proxy-Protocol is used with an attacker-controlled proxy, has an out-of-bounds write.
How severe is CVE-2026-94054?: CVE-2026-94054 has a CVSS 3.x base score of 7.0, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability low.
Is CVE-2026-94054 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-94054?: CVE-2026-94054 affects Exim. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-94054?: 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-2026-94054 published?: CVE-2026-94054 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:*:*:*:*:*:*:*:*

More vulnerabilities in Exim

CVE-2026-45185 — Critical (CVSS 9.8): Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing…
CVE-2023-42117 — Critical (CVSS 9.8): Exim Improper Neutralization of Special Elements Remote Code Execution Vulnerability. This vulnerability allows remote…
CVE-2023-42116 — Critical (CVSS 9.8): Exim SMTP Challenge Stack-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote…
CVE-2023-42115 — Critical (CVSS 9.8): Exim AUTH Out-Of-Bounds Write Remote Code Execution Vulnerability. This vulnerability allows remote attackers to…
CVE-2022-37452 — Critical (CVSS 9.8): Exim before 4.95 has a heap-based buffer overflow for the alias list in host_name_lookup in host.c when…
CVE-2020-28026 — Critical (CVSS 9.8): Exim 4 before 4.94.2 has Improper Neutralization of Line Delimiters, relevant in non-default configurations that enable…

All CVEs affecting Exim →

Other CWE-787 (Out-of-bounds Write) vulnerabilities

CVE-2026-42369 — Critical (CVSS 10.0): GV-VMS V20 is a Video Monitoring Software used to gather the feeds of many surveillance cameras and manage other…
CVE-2026-4746 — Critical (CVSS 10.0): Out-of-bounds Write vulnerability in timeplus-io proton (base/poco/Foundation/src‎ modules). This vulnerability is…
CVE-2025-43300 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 15.8.5 and iPadOS…
CVE-2025-24201 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved checks to prevent unauthorized actions. This issue is fixed in…
CVE-2024-42479 — Critical (CVSS 10.0): llama.cpp provides LLM inference in C/C++. The unsafe `data` pointer member in the `rpc_tensor` structure can cause…
CVE-2024-39791 — Critical (CVSS 10.0): Stack-based buffer overflow vulnerabilities affecting Vonets industrial wifi bridge relays and wifi bridge…

Browse all CWE-787 (Out-of-bounds Write) 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)