# CVE-2026-8796: Sereal::Decoder versions before 5.005 for Perl allow heap out-of-bounds read via crafted input

> A heap out-of-bounds read in the Perl Sereal::Decoder library allows attackers to read sensitive memory or cause crashes via crafted input.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 31 May 2026
- **Updated:** 1 Jun 2026
- **Also known as:** DEBIAN-CVE-2026-8796, GHSA-xhpj-269v-vq2q, UBUNTU-CVE-2026-8796, openSUSE-SU-2026:10924-1

## What is CVE-2026-8796?

CVE-2026-8796 is a high-severity memory corruption vulnerability in YVES Sereal::Decoder, published on 31 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Sereal::Decoder versions before 5.005 for Perl allow heap out-of-bounds read via crafted input.

In Perl/Decoder/srl_decoder.c, srl_read_object() and srl_read_hash() process a COPY tag, a back-reference whose target byte the decoder re-decodes as a fresh tag. When that target byte matches the SHORT_BINARY pattern (an inline string whose length is encoded in the low bits of the tag), the resulting read is not bounded to precede the COPY tag's own offset and can run past the end of the input buffer. An attacker controlled COPY offset can land inside a previously decoded value rather than on a tag boundary, planting a byte that the decoder reads as a SHORT_BINARY tag and consuming up to 31 following bytes from the heap as a class name (OBJECT path) or hash key (HASH path).

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-8796?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `perl-Sereal-Decoder` | openSUSE:Tumbleweed | All versions | 5.6.0-1.1 |

## How do I fix CVE-2026-8796?

Upgrade to a fixed version.

## Is CVE-2026-8796 being exploited?

There is no known exploitation of CVE-2026-8796 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-8796 and fix it if it is affected.

What it is: CVE-2026-8796 is a high-severity memory corruption vulnerability in YVES Sereal::Decoder, published on 31 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-8796 in the wild and no public exploit code.

Affected product: YVES Sereal::Decoder. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-8796/ (Markdown: https://insights.sbomify.com/CVE-2026-8796/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-8796
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-8796
- OSV: https://osv.dev/vulnerability/CVE-2026-8796

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-8796/
Summaries are generated and may contain mistakes; the official description above is the record.