giflib: Double Free
CVE-2026-23868 is a high-severity double free vulnerability in giflib, with a CVSS 3.1 base score of 7.0 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected giflib versions: 5.0.0 through 6.1.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.17% 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 giflib you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on facebook.com for workarounds and exact fixed builds.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- 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:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by CNA.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 5.1 | Medium | CISA (ADP) |
| CVSS 3.1 | 7.0 | High | CNA |
Official description
Giflib contains a double-free vulnerability that is the result of a shallow copy in GifMakeSavedImage and incorrect error handling. The conditions needed to trigger this vulnerability are difficult but may be possible.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Double Free
The product calls free() twice on the same memory address.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly. If the language is object oriented, ensure that object destructors delete each chunk of memory only once.
- Use a static analysis tool to find double free instances.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- facebook.com/security/advisories/cve-2026-23868Third Party Advisory
Patches and release notes
Other references
- access.redhat.com/errata/RHSA-2026:16008
- access.redhat.com/errata/RHSA-2026:16009
- access.redhat.com/errata/RHSA-2026:16030
- access.redhat.com/errata/RHSA-2026:16174
- access.redhat.com/errata/RHSA-2026:19154
- access.redhat.com/errata/RHSA-2026:19367
- access.redhat.com/errata/RHSA-2026:19724
- access.redhat.com/errata/RHSA-2026:19725
- access.redhat.com/errata/RHSA-2026:25096
- access.redhat.com/errata/RHSA-2026:8858
- access.redhat.com/errata/RHSA-2026:8859
- access.redhat.com/errata/RHSA-2026:8861
- access.redhat.com/errata/RHSA-2026:8883
- access.redhat.com/errata/RHSA-2026:8884
- access.redhat.com/errata/RHSA-2026:8885
Recent Double Free vulnerabilities
- 7.5 High severity
- 7.8 High severity
- 7.8 High severity
- 7.5 High severity
- 7.8 High severity
- 7.8 High severity
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