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Fencer Vulns
medium 5.5

CVE-2026-81879 json

radare2: Heap out-of-bounds read in radare2 ELF PN_XNUM handling

published 2026-09-22 48 d ago modified 2026-09-25 45 d ago also EUVD-2026-84504

cvss
5.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits
0
none known

Summary

radare2 is a UNIX-like reverse engineering framework and command-line toolset. Prior to 6.2.0, radare2's ELF PN_XNUM handling was vulnerable because the ELF parser allocated the program-header array using the resolved PN_XNUM count but several consumers still iterated with the original e_phnum value of 65535. The vulnerability is triggered by processing a crafted ELF file with e_phnum = 0xffff and a much smaller resolved count in shdr[0].sh_info. Consumers iterated beyond the allocated program-header array. This can cause a heap out-of-bounds read and process termination, resulting in denial of service; memory disclosure and code execution have not been demonstrated. This issue is fixed in version 6.2.0.

Patch / fix

  • radare radare2 6.2.0
  • radare2 openSUSE Leap 16.0 6.2.2-bp160.1.1

opensuse advisories openSUSE-SU-2026:21988-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-81879 updated cvss 5.5

radare2: radare2: Denial of Service via heap out-of-bounds read in ELF file parsing

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
48 d ago

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/radareorg/radare2/issues/26223 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD 3.1 6.1 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H

Affected products

  • radareorg radare2

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.