Skip to content
Patch Next
Sign inAdd to your agent

← Actionable
High, CVSS 8.7amended

iskorotkov/avro: Denial-of-Service Vulnerability in Decoder

GHSA-mx64-mj3q-7prj

What to do

Partial vendor fix. Follow the primary source's mitigation guidance and check back for a fix.

This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.

Add to your agent

Affected packages

  • Go github.com/hamba/avro/v2

    Affected
    every version
    Fixed in
    no fixed version recorded

  • Go github.com/iskorotkov/avro/v2

    Affected
    < 2.33.0
    Fixed in
    2.33.0

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS 4.0
8.7 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N · score source
EPSS
No dated EPSS signal available.
Source description

As published by the source; long descriptions are shortened.

Memory Exhaustion via Unbounded Map Allocations in Avro Decoder Summary The Avro map decoder accepted attacker-controlled block-element counts from the wire format and grew the destination map without enforcing an upper bound. The slice decoder already had Config.MaxSliceAllocSize for the equivalent attack against arrays; the map decoder had no analogous limit, so a producer could declare an arbitrarily large map (in one block, or chunked across many sub-limit blocks) and exhaust process memory until the OOM killer fired. The fix introduces Config.MaxMapAllocSize with cumulative enforcement across block boundaries. The new limit is opt-in: the field defaults to zero, which preserves the previous unbounded behavior for backward compatibility. Upgrading to v2.33.0 alone does not mitigate the issue — consumers of untrusted Avro data must explicitly set MaxMapAllocSize on their avro.Config. Description Avro maps are encoded as a sequence of blocks; each block declares a long element…

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 3 · amended ·

    Amended from ghsa record GHSA-mx64-mj3q-7prj

  2. Revision 2 · amended ·

    Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

  3. Revision 1 · created ·

    Published from osv record GO-2026-5048

Agent brief

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: GHSA-mx64-mj3q-7prj

Advisory: iskorotkov/avro: Denial-of-Service Vulnerability in Decoder
IDs: GHSA-mx64-mj3q-7prj
Record: https://patchnext.com/advisories/go-2026-5048 (revision 3, source checked 26 Oct 2026, 15:22 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Partial vendor fix; fixed versions by package: github.com/iskorotkov/avro/v2 2.33.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/hamba/avro/v2: affected every version
- Go github.com/iskorotkov/avro/v2: affected < 2.33.0; fixed in 2.33.0

## Suggested inspection (read-only)
- Go github.com/hamba/avro/v2: check the installed version with your package manager.
- Go github.com/iskorotkov/avro/v2: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/hamba/avro/v2, github.com/iskorotkov/avro/v2.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GO-2026-5048 (OSV record GO-2026-5048 lists affected ranges: Go github.com/iskorotkov/avro/v2 >=0 =0)
- Verified: https://github.com/advisories/GHSA-mx64-mj3q-7prj (GitHub-reviewed advisory GHSA-mx64-mj3q-7prj lists affected ranges: Go github.com/iskorotkov/avro/v2 >=0 <2.33.0)

Commands are suggestions: review each one before running it.

Loading voting…