# CVE-2026-45185: exim4: Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsin...

CVE-2026-45185 is fixed in 6 products on 1 platform, first by exim4 4.99.1-1ubuntu1.2, released May 12, 2026. It is not reported as exploited. Patch Radar priority: Urgent.

- Web page: https://patchblox.com/security/cve/CVE-2026-45185
- Priority: Urgent
- CVSS: 9.8 (critical)
- EPSS: 0.0127
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 12, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | exim4 Debian 12.15 (bookworm) | 4.96-15+deb12u9 | [DEBIAN-CVE-2026-45185](https://patchblox.com/security/data/fix/linux/debian-cve-2026-45185.md) | May 15, 2026 |
| Linux | exim4 Debian 13.5 (trixie) | 4.98.2-1+deb13u2 | [DEBIAN-CVE-2026-45185](https://patchblox.com/security/data/fix/linux/debian-cve-2026-45185.md) | May 15, 2026 |
| Linux | exim4 Debian 14 | 4.99.2-2 | [DEBIAN-CVE-2026-45185](https://patchblox.com/security/data/fix/linux/debian-cve-2026-45185.md) | May 15, 2026 |
| Linux | exim4 Ubuntu 20.04 LTS (focal) | 4.93-13ubuntu1.12+esm1 | [exim4 4.93-13ubuntu1.12+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-exim4-4.93-13ubuntu1.12-esm1.md) | Jun 24, 2026 |
| Linux | exim4 Ubuntu 22.04.1 LTS (jammy) | 4.95-4ubuntu2.8 | [exim4 4.95-4ubuntu2.8](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-exim4-4.95-4ubuntu2.8.md) | May 27, 2026 |
| Linux | exim4 Ubuntu 24.04.5 LTS (noble) | 4.97-4ubuntu4.5 | [exim4 4.97-4ubuntu4.5](https://patchblox.com/security/data/fix/linux/ubuntu-noble-exim4-4.97-4ubuntu4.5.md) | May 27, 2026 |
| Linux | exim4 Ubuntu 25.10 (questing) | 4.98.2-1ubuntu2.2 | [exim4 4.98.2-1ubuntu2.2](https://patchblox.com/security/data/fix/linux/ubuntu-questing-exim4-4.98.2-1ubuntu2.2.md) | May 27, 2026 |
| Linux | exim4 Ubuntu 26.04.1 LTS (resolute) | 4.99.1-1ubuntu1.2 | [exim4 4.99.1-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-exim4-4.99.1-1ubuntu1.2.md) | May 12, 2026 |
| Linux | exim4-base Ubuntu 20.04 LTS (focal) | 4.93-13ubuntu1.12+esm1 | [exim4-base 4.93-13ubuntu1.12+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-exim4-base-4.93-13ubuntu1.12-esm1.md) | Jun 24, 2026 |
| Linux | exim4-base Ubuntu 22.04.1 LTS (jammy) | 4.95-4ubuntu2.8 | [exim4-base 4.95-4ubuntu2.8](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-exim4-base-4.95-4ubuntu2.8.md) | May 27, 2026 |
| Linux | exim4-base Ubuntu 24.04.5 LTS (noble) | 4.97-4ubuntu4.5 | [exim4-base 4.97-4ubuntu4.5](https://patchblox.com/security/data/fix/linux/ubuntu-noble-exim4-base-4.97-4ubuntu4.5.md) | May 27, 2026 |
| Linux | exim4-base Ubuntu 25.10 (questing) | 4.98.2-1ubuntu2.2 | [exim4-base 4.98.2-1ubuntu2.2](https://patchblox.com/security/data/fix/linux/ubuntu-questing-exim4-base-4.98.2-1ubuntu2.2.md) | May 27, 2026 |
| Linux | exim4-base Ubuntu 26.04.1 LTS (resolute) | 4.99.1-1ubuntu1.2 | [exim4-base 4.99.1-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-exim4-base-4.99.1-1ubuntu1.2.md) | May 12, 2026 |
| Linux | exim4-config Ubuntu 20.04 LTS (focal) | 4.93-13ubuntu1.12+esm1 | [exim4-config 4.93-13ubuntu1.12+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-exim4-config-4.93-13ubuntu1.12-esm1.md) | Jun 24, 2026 |
| Linux | exim4-config Ubuntu 22.04.1 LTS (jammy) | 4.95-4ubuntu2.8 | [exim4-config 4.95-4ubuntu2.8](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-exim4-config-4.95-4ubuntu2.8.md) | May 27, 2026 |
| Linux | exim4-config Ubuntu 24.04.5 LTS (noble) | 4.97-4ubuntu4.5 | [exim4-config 4.97-4ubuntu4.5](https://patchblox.com/security/data/fix/linux/ubuntu-noble-exim4-config-4.97-4ubuntu4.5.md) | May 27, 2026 |
| Linux | exim4-config Ubuntu 25.10 (questing) | 4.98.2-1ubuntu2.2 | [exim4-config 4.98.2-1ubuntu2.2](https://patchblox.com/security/data/fix/linux/ubuntu-questing-exim4-config-4.98.2-1ubuntu2.2.md) | May 27, 2026 |
| Linux | exim4-config Ubuntu 26.04.1 LTS (resolute) | 4.99.1-1ubuntu1.2 | [exim4-config 4.99.1-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-exim4-config-4.99.1-1ubuntu1.2.md) | May 12, 2026 |
| Linux | exim4-daemon-heavy Ubuntu 20.04 LTS (focal) | 4.93-13ubuntu1.12+esm1 | [exim4-daemon-heavy 4.93-13ubuntu1.12+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-exim4-daemon-heavy-4.93-13ubuntu1.12-esm1.md) | Jun 24, 2026 |
| Linux | exim4-daemon-heavy Ubuntu 22.04.1 LTS (jammy) | 4.95-4ubuntu2.8 | [exim4-daemon-heavy 4.95-4ubuntu2.8](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-exim4-daemon-heavy-4.95-4ubuntu2.8.md) | May 27, 2026 |
| Linux | exim4-daemon-heavy Ubuntu 24.04.5 LTS (noble) | 4.97-4ubuntu4.5 | [exim4-daemon-heavy 4.97-4ubuntu4.5](https://patchblox.com/security/data/fix/linux/ubuntu-noble-exim4-daemon-heavy-4.97-4ubuntu4.5.md) | May 27, 2026 |
| Linux | exim4-daemon-heavy Ubuntu 25.10 (questing) | 4.98.2-1ubuntu2.2 | [exim4-daemon-heavy 4.98.2-1ubuntu2.2](https://patchblox.com/security/data/fix/linux/ubuntu-questing-exim4-daemon-heavy-4.98.2-1ubuntu2.2.md) | May 27, 2026 |
| Linux | exim4-daemon-heavy Ubuntu 26.04.1 LTS (resolute) | 4.99.1-1ubuntu1.2 | [exim4-daemon-heavy 4.99.1-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-exim4-daemon-heavy-4.99.1-1ubuntu1.2.md) | May 12, 2026 |
| Linux | exim4-daemon-light Ubuntu 20.04 LTS (focal) | 4.93-13ubuntu1.12+esm1 | [exim4-daemon-light 4.93-13ubuntu1.12+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-exim4-daemon-light-4.93-13ubuntu1.12-esm1.md) | Jun 24, 2026 |
| Linux | exim4-daemon-light Ubuntu 22.04.1 LTS (jammy) | 4.95-4ubuntu2.8 | [exim4-daemon-light 4.95-4ubuntu2.8](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-exim4-daemon-light-4.95-4ubuntu2.8.md) | May 27, 2026 |
| Linux | exim4-daemon-light Ubuntu 24.04.5 LTS (noble) | 4.97-4ubuntu4.5 | [exim4-daemon-light 4.97-4ubuntu4.5](https://patchblox.com/security/data/fix/linux/ubuntu-noble-exim4-daemon-light-4.97-4ubuntu4.5.md) | May 27, 2026 |
| Linux | exim4-daemon-light Ubuntu 25.10 (questing) | 4.98.2-1ubuntu2.2 | [exim4-daemon-light 4.98.2-1ubuntu2.2](https://patchblox.com/security/data/fix/linux/ubuntu-questing-exim4-daemon-light-4.98.2-1ubuntu2.2.md) | May 27, 2026 |
| Linux | exim4-daemon-light Ubuntu 26.04.1 LTS (resolute) | 4.99.1-1ubuntu1.2 | [exim4-daemon-light 4.99.1-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-exim4-daemon-light-4.99.1-1ubuntu1.2.md) | May 12, 2026 |
| Linux | eximon4 Ubuntu 20.04 LTS (focal) | 4.93-13ubuntu1.12+esm1 | [eximon4 4.93-13ubuntu1.12+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-eximon4-4.93-13ubuntu1.12-esm1.md) | Jun 24, 2026 |
| Linux | eximon4 Ubuntu 22.04.1 LTS (jammy) | 4.95-4ubuntu2.8 | [eximon4 4.95-4ubuntu2.8](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-eximon4-4.95-4ubuntu2.8.md) | May 27, 2026 |
| Linux | eximon4 Ubuntu 24.04.5 LTS (noble) | 4.97-4ubuntu4.5 | [eximon4 4.97-4ubuntu4.5](https://patchblox.com/security/data/fix/linux/ubuntu-noble-eximon4-4.97-4ubuntu4.5.md) | May 27, 2026 |
| Linux | eximon4 Ubuntu 25.10 (questing) | 4.98.2-1ubuntu2.2 | [eximon4 4.98.2-1ubuntu2.2](https://patchblox.com/security/data/fix/linux/ubuntu-questing-eximon4-4.98.2-1ubuntu2.2.md) | May 27, 2026 |
| Linux | eximon4 Ubuntu 26.04.1 LTS (resolute) | 4.99.1-1ubuntu1.2 | [eximon4 4.99.1-1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-eximon4-4.99.1-1ubuntu1.2.md) | May 12, 2026 |

---

Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.