CVE-2026-5435

Potential buffer overflow in ns_sprintrrf TSIG handling path

HIGH
7.3
CVSS Score
Published: April 28, 2026 at 11:58 AM UTC
Updated: October 15, 2026 at 01:12 AM UTC
5 products affected across 3 vendorsGlibcSIMATIC S7-1500 CPU 1518-4 Pn /dp MFP FirmwareSiplus S7-1500 CPU 1518-4 Pn /dp MFP Firmware

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Severity
HIGH7.3
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

The deprecated functions ns_printrrf, ns_printrr and fp_nquery in the GNU C Library version 2.2 and newer fail to enforce the caller-supplied buffer length, and can result in an out-of-bounds write when printing TSIG records.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≥ 2.2
V3.1.5 ≤ v < V3.1.63.1.5
Affected range stops below V3.1.6, so it looks safe — our inference, not a vendor statement
V3.1.5 ≤ v < V3.1.63.1.5
Affected range stops below V3.1.6, so it looks safe — our inference, not a vendor statement
V3.1.5 ≤ v < V3.1.63.1.5
Affected range stops below V3.1.6, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (3)

Mailing ListThird Party Advisory
Source: cverecord
https://inbox.sourceware.org/libc-announce/[email protected]/T/#u
Source: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
https://cert-portal.siemens.com/productcert/html/ssa-082556.html

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.3HIGH134c704f-9b21-4f2e-91b3-4a467353bcc0
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
LOW
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-787

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