# RHSA-2026:65534: image-builder security update

RHSA-2026:65534, released September 10, 2026, fixes 14 CVEs in image-builder (version 52.1-1.el10_2.2). None of them is reported as exploited. Patch Radar priority: Urgent.

- Web page: https://patchblox.com/security/fix/linux/rhsa-2026-65534
- Platform: Linux
- Released: Sep 10, 2026
- Priority: Urgent (Closes CVE-2026-39821, rated Critical)
- CVEs: 14, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://access.redhat.com/errata/RHSA-2026:65534

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [image-builder](https://patchblox.com/security/data/product/linux/image-builder.md) | RHEL 10 | 52.1-1.el10_2.2 |

## CVEs this fix closes

| CVE | Priority | Title | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2026-39821](https://patchblox.com/security/data/cve/CVE-2026-39821.md) | Urgent | Invoking failure to reject ASCII-only Punycode-encoded labels in golang.org/x/net/idna | 10.0 | 0.0183 |  |
| [CVE-2026-33811](https://patchblox.com/security/data/cve/CVE-2026-33811.md) | High | Crash when handling long CNAME response in net | 8.8 | 0.0088 |  |
| [CVE-2026-42499](https://patchblox.com/security/data/cve/CVE-2026-42499.md) | High | Quadratic string concatenation in consumePhrase in net/mail | 8.8 | 0.0080 |  |
| [CVE-2026-39820](https://patchblox.com/security/data/cve/CVE-2026-39820.md) | High | Quadratic string concatentation in consumeComment in net/mail | 8.8 | 0.0078 |  |
| [CVE-2026-32280](https://patchblox.com/security/data/cve/CVE-2026-32280.md) | High | Unexpected work during chain building in crypto/x509 | 9.1 | 0.0063 |  |
| [CVE-2026-33818](https://patchblox.com/security/data/cve/CVE-2026-33818.md) | High | Enforce maximum recursion depth in encoding/asn1 | 8.8 | 0.0057 |  |
| [CVE-2026-56853](https://patchblox.com/security/data/cve/CVE-2026-56853.md) | High | Apply ReadHeaderTimeout when doing unencrypted HTTP/2 check in net/http | 8.8 | 0.0057 |  |
| [CVE-2026-56859](https://patchblox.com/security/data/cve/CVE-2026-56859.md) | High | Add recursion depth guard during decode in encoding/xml | 8.8 | 0.0057 |  |
| [CVE-2026-56862](https://patchblox.com/security/data/cve/CVE-2026-56862.md) | High | Limit handshake messages we are willing to accept post-handshake in crypto/tls | 8.8 | 0.0057 |  |
| [CVE-2026-42504](https://patchblox.com/security/data/cve/CVE-2026-42504.md) | High | Quadratic complexity in WordDecoder.DecodeHeader in mime | 8.8 | 0.0056 |  |
| [CVE-2026-56860](https://patchblox.com/security/data/cve/CVE-2026-56860.md) | High | Avoid quadratic complexity in resolvePath in net/url | 8.8 | 0.0055 |  |
| [CVE-2026-32281](https://patchblox.com/security/data/cve/CVE-2026-32281.md) | High | Inefficient policy validation in crypto/x509 | 9.1 | 0.0036 |  |
| [CVE-2026-33810](https://patchblox.com/security/data/cve/CVE-2026-33810.md) | High | Case-sensitive excludedSubtrees name constraints cause Auth Bypass in crypto/x509 | 9.1 | 0.0035 |  |
| [CVE-2026-56858](https://patchblox.com/security/data/cve/CVE-2026-56858.md) | High | Fix Javascript regexp context tracking in html/template | 8.8 | 0.0031 |  |

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Data as of 2026-11-07T12:40:37Z 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

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