7.5

CVE-2026-31638: rxrpc: Only put the call ref if one was acquired

Modified
AliasesUBUNTU-CVE-2026-31638DEBIAN-CVE-2026-31638
Published 24-04-2026Last modified 19-10-2026

Vulnerability summary

CVE-2026-31638 is a high (CVSS 7.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.44% chance of exploitation in the next 30 days, higher than 38.3% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.44%
0%100%
Low · -0.19 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 16 · Related 14
MGASA-2026-0108MGASA-2026-0110USN-8567-1USN-8574-1USN-8574-2USN-8574-3

Timeline

  1. 24-04-2026
    PublishedVulnerability first disclosed.
  2. 19-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Only put the call ref if one was acquired rxrpc_input_packet_on_conn() can process a to-client packet after the current client call on the channel has already been torn down. In that case chan->call is NULL, rxrpc_try_get_call() returns NULL and there is no reference to drop. The client-side implicit-end error path does not account for that and unconditionally calls rxrpc_put_call(). This turns a protocol error path into a kernel crash instead of rejecting the packet. Only drop the call reference if one was actually acquired. Keep the existing protocol error handling unchanged.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.44%

Chance of exploitation in the next 30 days

Percentile

38%

Versus all other CVEs

30-day change

Decrease -0.19 pp

From 0.63% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu130 products
  • linux< 6.8.0-136.136 | All versions (No fix recorded)
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 6.8.0-1061.64 | All versions (No fix recorded)
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 5e6ef4f1017c7f844e305283bbd8875af475e2fc, < b8f66447448d6c305a51413a67ec8ed26aa7d1dd | ≥ 5e6ef4f1017c7f844e305283bbd8875af475e2fc, < 0c156aff8a2d4fa0d61db7837641975cf0e5452d | ≥ 5e6ef4f1017c7f844e305283bbd8875af475e2fc, < 8299ca146489664e3c0c90a3b8900d8335b1ede4 | ≥ 5e6ef4f1017c7f844e305283bbd8875af475e2fc, < 9fb09861e2b8d1abfe2efaf260c9f1d30080ea38 | ≥ 5e6ef4f1017c7f844e305283bbd8875af475e2fc, < 6331f1b24a3e85465f6454e003a3e6c22005a5c5 | 6.2
  • linux_kernelEOL≥ 6.2.1, < 6.6.135 | ≥ 6.7, < 6.12.82 | ≥ 6.13, < 6.18.23 | ≥ 6.19, < 6.19.13 | 6.2 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3 | 7.0:rc4 | 7.0:rc5 | 7.0:rc6 | 7.0:rc7
Debian1 product
  • linux< 6.12.85-1 | < 6.19.13-1

3 vendors · 133 products

References

24 links
Show all 24 references