CVE-2026-34501 — apr-util
HIGHCVE-2026-34501 is a high-severity (CVSS 7.5) CWE-122 vulnerability. A fix is available — see the affected versions and patch details below.
Apache Portable Runtime Utility: Heap buffer overflow in APR redis client
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-34501.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Description
Heap-based Buffer Overflow vulnerability in Apache Portable Runtime Utility redis client.
This issue affects Apache Portable Runtime Utility: from 1.6.0 through 1.6.3.
Users are recommended to upgrade to version 1.6.4, which fixes the issue.
Affected Products
apr-utilapacheDetection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Fix
Upgrade the affected component to the fixed release for CVE-2026-34501, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.
Workarounds
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
The impact of this vulnerability is rated as Moderate. Although the flaw involves a heap buffer overflow and the CVSS base score reflects an unauthenticated network vector, exploitation requires the attacker to control or compromise the Redis server that the application queries. An attacker cannot trigger this…
Ensure that the Redis server used by the application is deployed in a trusted, network-segregated environment and is not accessible to untrusted parties. Where possible, configure authentication and TLS on the Redis connection to reduce the risk of a compromised or spoofed Redis server.Source: Red Hat security advisory for CVE-2026-34501 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 10 | apr-util-0:1.6.3-23.el10_2.1 | RHSA-2026:66392 |
| Red Hat Enterprise Linux 8 | apr-util-0:1.6.1-9.el8_10.1 | RHSA-2026:69113 |
| Red Hat Enterprise Linux 9 | apr-util-0:1.6.1-23.el9_8.1 | RHSA-2026:66341 |
| Red Hat Hardened Images | apr-util-main-1.6.5-1.hum1 | RHSA-2026:58474 |
Frequently Asked Questions
Is CVE-2026-34501 in your dependencies?
Find it across your dependency tree, including transitive dependencies.