LibRaw: Improper Validation of Array Index
CVE-2026-21413 is a critical-severity improper validation of array index vulnerability in LibRaw, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected LibRaw versions: Commit 0b56545; Commit d20315b. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.41% chance of exploitation within 30 days, higher than 73% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of LibRaw 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
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
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (cisco.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | CNA (cisco.com) |
| CVSS 3.1 | 7.5 | High | CNA |
Official description
A heap-based buffer overflow vulnerability exists in the lossless_jpeg_load_raw functionality of LibRaw Commit 0b56545 and Commit d20315b. A specially crafted malicious file can lead to a heap buffer overflow. An attacker can provide a malicious file to trigger this vulnerability.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Validation of Array Index
The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.
How developers prevent this class of flaw
- Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, Ada allows the programmer to constrain the values of a variable and languages such as Java and Ruby will allow the programmer to handle exceptions when an out-of-bounds index is accessed.
- Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment. For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND.
More Improper Validation of Array Index vulnerabilities (CWE-129)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Technical write-ups (may include proof of concept)
- talosintelligence.com/vulnerability_reports/TALOS-2026-2331Exploit, Third Party Advisory
- talosintelligence.com/vulnerability_reports/TALOS-2026-2331Exploit, Third Party Advisory
Other references
- access.redhat.com/errata/RHSA-2026:11360
- access.redhat.com/errata/RHSA-2026:13284
- access.redhat.com/errata/RHSA-2026:13854
- access.redhat.com/errata/RHSA-2026:13860
- access.redhat.com/errata/RHSA-2026:13868
- access.redhat.com/errata/RHSA-2026:13870
- access.redhat.com/errata/RHSA-2026:14224
- access.redhat.com/errata/RHSA-2026:14655
- access.redhat.com/errata/RHSA-2026:14673
- access.redhat.com/errata/RHSA-2026:19345
- access.redhat.com/security/cve/CVE-2026-21413
- bugzilla.redhat.com/show_bug.cgi?id=2455929
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-21413.json
Other vulnerabilities in LibRaw
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.1 Critical severity
Recent Improper Validation of Array Index vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.8 High severity
- 7.5 High severity
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