CVE-2023-45661: Wild address read in stbi__gif_load_next in stb_image

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-10-21 · updated 2026-06-17
Weakness: CWE-125

Description

stb_image is a single file MIT licensed library for processing images. A crafted image file may trigger out of bounds memcpy read in `stbi__gif_load_next`. This happens because two_back points to a memory address lower than the start of the buffer out. This issue may be used to leak internal memory allocation information.

Affected products

nothings stb: 2.28

References

https://github.com/nothings/stb/blob/5736b15f7ea0ffb08dd38af21067c314d6a3aae9/stb_image.h#L6817
https://github.com/nothings/stb/blob/5736b15f7ea0ffb08dd38af21067c314d6a3aae9/stb_image.h#L7021-L7022
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NMXKOKPP4BKTNUTF5KSRDQAWOUILQZNO/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QVABVF4GEM6BYD5L4L64RCRSXUHY6LGN/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UVQ7ONFH5GWLMXYEAJG32A3EUKUCEVCR/
https://securitylab.github.com/advisories/GHSL-2023-145_GHSL-2023-151_stb_image_h/
https://github.com/nothings/stb/blob/5736b15f7ea0ffb08dd38af21067c314d6a3aae9/stb_image.h#L6817
https://github.com/nothings/stb/blob/5736b15f7ea0ffb08dd38af21067c314d6a3aae9/stb_image.h#L7021-L7022
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NMXKOKPP4BKTNUTF5KSRDQAWOUILQZNO/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QVABVF4GEM6BYD5L4L64RCRSXUHY6LGN/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UVQ7ONFH5GWLMXYEAJG32A3EUKUCEVCR/
https://securitylab.github.com/advisories/GHSL-2023-145_GHSL-2023-151_stb_image_h/

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