How severe is CVE-2026-45185?

CVE-2026-45185 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-45185 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-45185?

CVE-2026-45185 affects Exim. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-45185?

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

Does CVE-2026-45185 have an EU (EUVD) identifier?

Yes. CVE-2026-45185 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29824.

When was CVE-2026-45185 published?

CVE-2026-45185 was published on 2026-05-12 and last updated on 2026-06-17.

CVE-2026-45185

CVE-2026-45185 is a critical-severity vulnerability in Exim with a CVSS 3.x base score of 9.8. 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-416.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (65th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-29824
Weakness: CWE-416
Affected product: Exim
Published: 2026-05-12
Last modified: 2026-06-17

Description

Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing path. It is triggered when a client sends a TLS close_notify mid-body during a CHUNKING transfer, followed by a final cleartext byte on the same TCP connection. This can lead to heap corruption. An unauthenticated network attacker exploiting this vulnerability could execute arbitrary code.

Frequently asked questions

What is CVE-2026-45185?: Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing path. It is triggered when a client sends a TLS close_notify mid-body during a CHUNKING transfer, followed by a final cleartext byte on the same TCP connection. This can lead to heap corruption. An unauthenticated network attacker exploiting this vulnerability could execute arbitrary code.
How severe is CVE-2026-45185?: CVE-2026-45185 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-45185 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-45185?: CVE-2026-45185 affects Exim. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-45185?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-45185 have an EU (EUVD) identifier?: Yes. CVE-2026-45185 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29824.
When was CVE-2026-45185 published?: CVE-2026-45185 was published on 2026-05-12 and last updated on 2026-06-17.

References

Affected products (1)

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

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Other CWE-416 (Use After Free) vulnerabilities

CVE-2026-13782 — Critical (CVSS 10.0): Use after free in Browser in Google Chrome prior to 150.0.7871.47 allowed a remote attacker who had compromised the…
CVE-2026-4725 — Critical (CVSS 10.0): Sandbox escape due to use-after-free in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 149…
CVE-2026-4688 — Critical (CVSS 10.0): Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox…
CVE-2025-24085 — Critical (CVSS 10.0): A use after free issue was addressed with improved memory management. This issue is fixed in iOS 18.3 and iPadOS 18.3,…
CVE-2024-43102 — Critical (CVSS 10.0): Concurrent removals of certain anonymous shared memory mappings by using the UMTX_SHM_DESTROY sub-request of…
CVE-2021-32495 — Critical (CVSS 10.0): Radare2 has a use-after-free vulnerability in pyc parser's get_none_object function. Attacker can read freed memory…

Browse all CWE-416 (Use After Free) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

88.212.209.244 (ipv4-addr)
147.50.227.79 (ipv4-addr)
161.35.169.21 (ipv4-addr)
198.57.247.251 (ipv4-addr)
108.181.2.217 (ipv4-addr)
188.241.222.89 (ipv4-addr)
74.91.200.217 (ipv4-addr)
162.214.159.200 (ipv4-addr)