Red Hat Enterprise Linux 6: Buffer Underwrite
CVE-2026-34253 is a high-severity buffer underwrite vulnerability in Red Hat Enterprise Linux 6 from Red Hat, with a CVSS 3.1 base score of 8.2 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.56% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Red Hat Enterprise Linux 6 you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 6 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 7 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8 | Not specified in the record | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- LowLimited modification of data is possible.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H. Scored by CNA.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.2 | High | CISA (ADP) |
| CVSS 3.1 | 8.2 | High | CNA |
Official description
A buffer underflow vulnerability has been identified in the ogg123 utility from the vorbis-tools 1.4.3 package in function remotethread in remote.c. This vulnerability occurs in the remote control functionality when processing malformed input, leading to a stack buffer underflow that can cause application crashes and potentially allow code execution.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Buffer Underwrite
The product writes to a buffer using an index or pointer that references a memory location prior to the beginning of the buffer.
How developers prevent this class of flaw
- Choose a language that is not susceptible to these issues.
- All calculated values that are used as index or for pointer arithmetic should be validated to ensure that they are within an expected range.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
- github.com/xiph/vorbis-tools/archive/refs/tags/v1.4.3.tar.gz
- github.com/xiph/vorbis-tools/blob/0b3fbf42eb3897d32f4a75baa2dc915a4ca45e8e/ogg123/remote.c#L153
- gitlab.xiph.org/xiph/vorbis-tools/-/work_items/2332
- access.redhat.com/security/cve/CVE-2026-34253
- bugzilla.redhat.com/show_bug.cgi?id=2477925
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34253.json
Other vulnerabilities in Red Hat Enterprise Linux 6
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.9 High severity
- 7.6 High severity
- 7.5 High severity
Recent Buffer Underwrite vulnerabilities
- 7.3 High severity
- 8.2 High severity
- 8.1 High severity
- 7.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
Spotted an error? Tell us.