CVE-2019-19777: stb_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.
Noroxi assessment
Priority: Monitor (action score 35/100)
- 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: 1.3% (FIRST EPSS); higher than 72.7% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
- Fixed version: libsixel (Debian:12) 1.8.6-1.
Low priority for now. Upgrade to libsixel (Debian:12) 1.8.6-1 or later.
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
- Published
- Dec 12, 2019
- Updated
- Jun 16, 2026
- EPSS
- 1.3% · 72th percentile
- CWE
- CWE-125
Report tools
Action score
35
Low priority for now.
- CVSS
- 35 / 40 · 8.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.3%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi 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.
We use this product, ask for helpAffected 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 |
| saitoha | libsixel | cpe:2.3:a:saitoha:libsixel |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- nothings stb image.h2.23
- saitoha libsixel1.8.2
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | libsixel | before 1.8.6-1 | 1.8.6-1 |
Same product
nothings: all recordsOther highest-scoring records for the same primary product.
- CVE-2023-45666Possible double-free or memory leak in stbi__load_gif_main in stb_image39Monitor
- CVE-2023-45664Double-free in stbi__load_gif_main_outofmem in stb_image35Monitor
- 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
Published before and after this one in the same product
- ← EarlierCVE-2018-16981Sep 12, 2018 · stb stb_image.h 2.19, as used in catimg, Emscripten, and other products, has a heap-based buffer overflow in the stbi__out_gif_code…35Monitor
- Later →CVE-2019-20056Dec 29, 2019 · stb_image.h (aka the stb image loader) 2.23, as used in libsixel and other products, has an assertion failure in stbi__shiftsigned.26Monitor
- Later →CVE-2021-42715Oct 21, 2021 · An issue was discovered in stb stb_image.h 1.33 through 2.27.22Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:libsixel | 1.8.6-1 · Debian:12 | Package registry (OSV) |
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.
Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- A user must open a link or visit a page.
- 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
- Required
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-125 · Out-of-bounds ReadCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log (1)
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →