6.3

CVE-2026-5123: osrg gobgp Numeric Errors

CVSS: 6.3v4.0MediumAnalyzed
AliasesUBUNTU-CVE-2026-5123DEBIAN-CVE-2026-5123
Published 30-03-2026Last modified 01-04-2026
Open JSON

Vulnerability summary

CVE-2026-5123 is a medium (CVSS 6.3) Numeric Errors vulnerability in osrg gobgp. EPSS estimates a 0.68% chance of exploitation in the next 30 days, higher than 51.3% of scored vulnerabilities.

Overall risk
25/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.3/10
010
Medium · v4.0 (CVE.org)
EPSS score
0.68%
0%100%
Low · +0.27 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 30-03-2026
    PublishedVulnerability first disclosed.
  2. 01-04-2026
    Last modifiedVulnerability information updated.

Description

A weakness has been identified in osrg GoBGP up to 4.3.0. This impacts the function DecodeFromBytes of the file pkg/packet/bgp/bgp.go. Executing a manipulation of the argument data[1] can lead to off-by-one. The attack may be launched remotely. Attacks of this nature are highly complex. The exploitability is said to be difficult. This patch is called 67c059413470df64bc20801c46f64058e88f800f. A patch should be applied to remediate this issue.

CVSS metrics

10 scores · 4 sources · 4 versions

EPSS trend

Probability

0.68%

Chance of exploitation in the next 30 days

Percentile

51%

Versus all other CVEs

30-day change

+0.27 pp

From 0.41% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.68%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • gobgpAll versions (No fix recorded) | < 4.4.0-1
Osrg1 product
  • gobgp4.0 | 4.1 | 4.2 | 4.3.0 | < 4.4.0
Ubuntu1 product
  • gobgpAll versions (No fix recorded)

3 vendors · 3 products

References

9 links