CVE-2026-5186: Nothings stb · Double Free
Affects Nothings stbSource CVE Database V5
Not known to be exploited · CVSS 4.8 Medium.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:PExploitation evidence
Disclosed: evidence found.
CVE published 31 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Nothingsstb | Affected
| Fixed in– |
AI-suggested
1. Restrict local access to systems running software that uses the stb library for image processing to trusted users only. 2. Audit all internal applications and third-party software to identify usage of stb_image.h, particularly for GIF handling. 3. Where possible, isolate or sandbox applications processing untrusted GIF images to limit potential damage from exploitation. 4. Monitor for unusual application crashes or memory errors that could indicate exploitation attempts. 5. Follow vendor and community channels closely for any forthcoming patches or updates addressing this vulnerability and apply them promptly. 6. Consider recompiling or replacing stb with a version that has been manually patched or with alternative image libraries if feasible. 7. Employ runtime protections such as memory corruption mitigations (ASLR, DEP, Control Flow Guard) to reduce exploitation success. 8. Implement strict file upload and processing policies to limit exposure to crafted GIF files from untrusted sources.
Description
A weakness has been identified in Nothings stb up to 2.30. This impacts the function stbi__load_gif_main of the file stb_image.h of the component Multi-frame GIF File Handler. This manipulation causes double free. The attack requires local access. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.