# CVE-2026-28388: NULL Pointer Dereference When Processing a Delta CRL

CVE-2026-28388 is fixed in 20 products on 1 platform, first by libssl3t64 3.5.5-1ubuntu3, released April 6, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-28388
- Priority: High
- CVSS: 7.5 (Moderate)
- EPSS: 0.0092
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 6, 2026
- Weakness: NULL Pointer Dereference
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-28388

## Description

This update for openssl-1_0_0 fixes the following issues  - CVE-2026-7383: Possible Heap Buffer Overflow in ASN.1 Multibyte String Conversion (bsc#1266340). - CVE-2026-9076: Out-of-Bounds Read in CMS Password-Based Decryption (bsc#1266341). - CVE-2026-28388: NULL Pointer Dereference When Processing a Delta CRL (bsc#1260442). - CVE-2026-28389: Possible NULL dereference when processing CMS KeyAgreeRecipientInfo (bsc#1260443). - CVE-2026-34180: Heap Buffer Over-read in ASN.1 Content Parsing (bsc#1266342). - CVE-2026-42766: Possible NULL Dereference in Password-Based CMS Decryption (bsc#1266349). - CVE-2026-45447: Heap Use-After-Free in OpenSSL PKCS7_verify() (bsc#1266357). - NULL pointer dereference when processing an OCSP response (bsc#1260446).

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libssl1.0.0 Ubuntu 18.04.6 LTS (bionic) | 1.0.2n-1ubuntu5.13+esm4 | [libssl1.0.0 1.0.2n-1ubuntu5.13+esm4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libssl1.0.0-1.0.2n-1ubuntu5.13-esm4.md) | Apr 15, 2026 |
| Linux | libssl1.1 Ubuntu 18.04.6 LTS (bionic) | 1.1.1-1ubuntu2.1~18.04.23+esm8 | [libssl1.1 1.1.1-1ubuntu2.1~18.04.23+esm8](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libssl1.1-1.1.1-1ubuntu2.1-18.04.23-esm8.md) | Apr 15, 2026 |
| Linux | libssl1.1 Ubuntu 20.04 LTS (focal) | 1.1.1f-1ubuntu2.24+esm3 | [libssl1.1 1.1.1f-1ubuntu2.24+esm3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libssl1.1-1.1.1f-1ubuntu2.24-esm3.md) | Apr 15, 2026 |
| Linux | libssl3 Ubuntu 22.04.1 LTS (jammy) | 3.0.2-0ubuntu1.23 | [libssl3 3.0.2-0ubuntu1.23](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libssl3-3.0.2-0ubuntu1.23.md) | Apr 15, 2026 |
| Linux | libssl3t64 Ubuntu 24.04.5 LTS (noble) | 3.0.13-0ubuntu3.9 | [libssl3t64 3.0.13-0ubuntu3.9](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libssl3t64-3.0.13-0ubuntu3.9.md) | Apr 15, 2026 |
| Linux | libssl3t64 Ubuntu 25.10 (questing) | 3.5.3-1ubuntu3.3 | [libssl3t64 3.5.3-1ubuntu3.3](https://patchblox.com/security/data/fix/linux/ubuntu-questing-libssl3t64-3.5.3-1ubuntu3.3.md) | Apr 15, 2026 |
| Linux | libssl3t64 Ubuntu 26.04.1 LTS (resolute) | 3.5.5-1ubuntu3 | [libssl3t64 3.5.5-1ubuntu3](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-libssl3t64-3.5.5-1ubuntu3.md) | Apr 6, 2026 |
| Linux | openssl Debian 12.15 (bookworm) | 3.0.19-1~deb12u2 | [DEBIAN-CVE-2026-28388](https://patchblox.com/security/data/fix/linux/debian-cve-2026-28388.md) | Apr 7, 2026 |
| Linux | openssl Debian 13.5 (trixie) | 3.5.5-1~deb13u2 | [DEBIAN-CVE-2026-28388](https://patchblox.com/security/data/fix/linux/debian-cve-2026-28388.md) | Apr 7, 2026 |
| Linux | openssl Debian 14 | 3.6.2-1 | [DEBIAN-CVE-2026-28388](https://patchblox.com/security/data/fix/linux/debian-cve-2026-28388.md) | Apr 7, 2026 |
| Linux | openssl Ubuntu 18.04.6 LTS (bionic) | 1.1.1-1ubuntu2.1~18.04.23+esm8 | [openssl 1.1.1-1ubuntu2.1~18.04.23+esm8](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-openssl-1.1.1-1ubuntu2.1-18.04.23-esm8.md) | Apr 15, 2026 |
| Linux | openssl Ubuntu 20.04 LTS (focal) | 1.1.1f-1ubuntu2.24+esm3 | [openssl 1.1.1f-1ubuntu2.24+esm3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-openssl-1.1.1f-1ubuntu2.24-esm3.md) | Apr 15, 2026 |
| Linux | openssl Ubuntu 22.04.1 LTS (jammy) | 3.0.2-0ubuntu1.23 | [openssl 3.0.2-0ubuntu1.23](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-openssl-3.0.2-0ubuntu1.23.md) | Apr 15, 2026 |
| Linux | openssl Ubuntu 24.04.5 LTS (noble) | 3.0.13-0ubuntu3.9 | [openssl 3.0.13-0ubuntu3.9](https://patchblox.com/security/data/fix/linux/ubuntu-noble-openssl-3.0.13-0ubuntu3.9.md) | Apr 15, 2026 |
| Linux | openssl Ubuntu 25.10 (questing) | 3.5.3-1ubuntu3.3 | [openssl 3.5.3-1ubuntu3.3](https://patchblox.com/security/data/fix/linux/ubuntu-questing-openssl-3.5.3-1ubuntu3.3.md) | Apr 15, 2026 |
| Linux | openssl Ubuntu 26.04.1 LTS (resolute) | 3.5.5-1ubuntu3 | [openssl 3.5.5-1ubuntu3](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-openssl-3.5.5-1ubuntu3.md) | Apr 6, 2026 |
| Linux | openssl amzn 2023 | 1:3.5.5-1.amzn2023.0.4 | [ALAS2023-2026-1586](https://patchblox.com/security/data/fix/linux/alas2023-2026-1586.md) | Apr 13, 2026 |
| Linux | openssl-1_0_0 opensuse-leap 15.6 | 1.0.2p-150000.3.105.1 | [SUSE-SU-2026:1291-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1291-1.md) | Apr 13, 2026 |
| Linux | openssl-1_0_0 sles 15.6 | 1.0.2p-150000.3.108.1 | [SUSE-SU-2026:2399-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2399-1.md) | Jun 15, 2026 |
| Linux | openssl-1_0_0 sles 15.6 | 1.0.2p-150000.3.105.1 | [SUSE-SU-2026:1291-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1291-1.md) | Apr 13, 2026 |
| Linux | openssl-1_0_0 sles 15.7 | 1.0.2p-150000.3.108.1 | [SUSE-SU-2026:2399-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2399-1.md) | Jun 15, 2026 |
| Linux | openssl-1_0_0 sles 15.7 | 1.0.2p-150000.3.105.1 | [SUSE-SU-2026:1291-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1291-1.md) | Apr 13, 2026 |
| Linux | openssl-1_1 sles 15.6 | 1.1.1w-150600.5.26.2 | [SUSE-SU-2026:1577-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1577-1.md) | Apr 23, 2026 |
| Linux | openssl-1_1 sles 15.7 | 1.1.1w-150700.11.16.1 | [SUSE-SU-2026:1386-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1386-1.md) | Apr 16, 2026 |
| Linux | openssl-3 opensuse-leap 15.6 | 3.1.4-150600.5.45.1 | [SUSE-SU-2026:1215-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1215-1.md) | Apr 8, 2026 |
| Linux | openssl-3 opensuse-leap 16.0 | 3.5.0-160000.7.1 | [OPENSUSE-SU-2026:20525-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-20525-1.md) | Apr 13, 2026 |
| Linux | openssl-3 sles 15.6 | 3.1.4-150600.5.45.1 | [SUSE-SU-2026:1215-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1215-1.md) | Apr 8, 2026 |
| Linux | openssl-3 sles 15.7 | 3.2.3-150700.5.31.1 | [SUSE-SU-2026:1375-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-1375-1.md) | Apr 15, 2026 |
| Linux | openssl-3 sles 16.0 | 3.5.0-160000.7.1 | [SUSE-SU-2026:21186-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-21186-1.md) | Apr 13, 2026 |
| Linux | openssl-debuginfo amzn 2023 | 1:3.5.5-1.amzn2023.0.4 | [ALAS2023-2026-1586](https://patchblox.com/security/data/fix/linux/alas2023-2026-1586.md) | Apr 13, 2026 |
| Linux | openssl-debugsource amzn 2023 | 1:3.5.5-1.amzn2023.0.4 | [ALAS2023-2026-1586](https://patchblox.com/security/data/fix/linux/alas2023-2026-1586.md) | Apr 13, 2026 |
| Linux | openssl-devel amzn 2023 | 1:3.5.5-1.amzn2023.0.4 | [ALAS2023-2026-1586](https://patchblox.com/security/data/fix/linux/alas2023-2026-1586.md) | Apr 13, 2026 |
| Linux | openssl-fips-provider-latest amzn 2023 | 1:3.5.5-1.amzn2023.0.4 | [ALAS2023-2026-1586](https://patchblox.com/security/data/fix/linux/alas2023-2026-1586.md) | Apr 13, 2026 |
| Linux | openssl-fips-provider-latest-debuginfo amzn 2023 | 1:3.5.5-1.amzn2023.0.4 | [ALAS2023-2026-1586](https://patchblox.com/security/data/fix/linux/alas2023-2026-1586.md) | Apr 13, 2026 |
| Linux | openssl-libs amzn 2023 | 1:3.5.5-1.amzn2023.0.4 | [ALAS2023-2026-1586](https://patchblox.com/security/data/fix/linux/alas2023-2026-1586.md) | Apr 13, 2026 |
| Linux | openssl-libs-debuginfo amzn 2023 | 1:3.5.5-1.amzn2023.0.4 | [ALAS2023-2026-1586](https://patchblox.com/security/data/fix/linux/alas2023-2026-1586.md) | Apr 13, 2026 |
| Linux | openssl-perl amzn 2023 | 1:3.5.5-1.amzn2023.0.4 | [ALAS2023-2026-1586](https://patchblox.com/security/data/fix/linux/alas2023-2026-1586.md) | Apr 13, 2026 |
| Linux | openssl-provider-legacy Ubuntu 25.10 (questing) | 3.5.3-1ubuntu3.3 | [openssl-provider-legacy 3.5.3-1ubuntu3.3](https://patchblox.com/security/data/fix/linux/ubuntu-questing-openssl-provider-legacy-3.5.3-1ubuntu3.3.md) | Apr 15, 2026 |
| Linux | openssl-provider-legacy Ubuntu 26.04.1 LTS (resolute) | 3.5.5-1ubuntu3 | [openssl-provider-legacy 3.5.5-1ubuntu3](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-openssl-provider-legacy-3.5.5-1ubuntu3.md) | Apr 6, 2026 |
| Linux | openssl-snapsafe-libs amzn 2023 | 1:3.5.5-1.amzn2023.0.4 | [ALAS2023-2026-1586](https://patchblox.com/security/data/fix/linux/alas2023-2026-1586.md) | Apr 13, 2026 |
| Linux | openssl-snapsafe-libs-debuginfo amzn 2023 | 1:3.5.5-1.amzn2023.0.4 | [ALAS2023-2026-1586](https://patchblox.com/security/data/fix/linux/alas2023-2026-1586.md) | Apr 13, 2026 |
| Linux | openssl1.0 Ubuntu 18.04.6 LTS (bionic) | 1.0.2n-1ubuntu5.13+esm4 | [openssl1.0 1.0.2n-1ubuntu5.13+esm4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-openssl1.0-1.0.2n-1ubuntu5.13-esm4.md) | Apr 15, 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.