NVD / CVE Program· CNA GitHub_M

CVE-2023-45666: Possible double-free or memory leak in stbi__load_gif_main in stb_image

Noroxi assessment

Priority: Monitor (action score 39/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 1% (FIRST EPSS); higher than 64.8% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
According to the record, no fixed version is available yet.
Severity is disputed: the assigning authority (CNA) scores it 7.3, NVD 9.8.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

stb_image is a single file MIT licensed library for processing images. It may look like `stbi__load_gif_main` doesn’t give guarantees about the content of output value `*delays` upon failure. Although it sets `*delays` to zero at the beginning, it doesn’t do it in case the image is not recognized as GIF and a call to `stbi__load_gif_main_outofmem` only frees possibly allocated memory in `*delays` without resetting it to zero. Thus it would be fair to say the caller of `stbi__load_gif_main` is responsible to free the allocated memory in `*delays` only if `stbi__load_gif_main` returns a non null value. However at the same time the function may return null value, but fail to free the memory in `*delays` if internally `stbi__convert_format` is called and fails. Thus the issue may lead to a memory leak if the caller chooses to free `delays` only when `stbi__load_gif_main` didn’t fail or to a double-free if the `delays` is always freed

CriticalCVSS 9.8 · v3.1—No exploit No fix recorded

BDU:2024-06918

Published: Oct 20, 2023
Updated: Jun 17, 2026
EPSS: 1.0% · 64th percentile
CWE: CWE-415

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 39 / 40 · 9.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 1.0%

CISA SSVC decision

Exploitation: proof of concept
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 9.8
CNA · GitHub_M: 7.3; 2.5 point gap

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
No fixed version yet

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
nothings	stb image.h	cpe:2.3:a:nothings:stb_image.h

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

nothings stb image.h2.28

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

nothings stb
- <= 2.28affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:12	libstb	from 0	—

Same product

nothings: all records

Other highest-scoring records for the same primary product.

CVE-2023-45664Double-free in stbi__load_gif_main_outofmem in stb_image
35Monitor
CVE-2022-28042stb_image.h v2.27 was discovered to contain an heap-based use-after-free via the function stbi__jpeg_huff_decode.
35Monitor
CVE-2019-19777stb_image.h (aka the stb image loader) 2.23, as used in libsixel and other products, has a heap-based buffer over-read in stbi__load_main.
35Monitor

Published before and after this one in the same product

← EarlierCVE-2023-45662Oct 20, 2023 · Multi-byte read heap buffer overflow in stbi__vertical_flip in stb_image
32Monitor
← EarlierCVE-2023-45663Oct 20, 2023 · Disclosure of uninitialized memory in stbi__tga_load in stb_image
22Monitor
Later →CVE-2023-45667Oct 20, 2023 · Null pointer dereference because of an uninitialized variable in stb_image
30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-415 · Double Free

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

github.com/nothings/stb/blob/5736b15f7ea0ffb08dd38af21067c314d6a3aae9/stb_image.h#L6957

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records